Managing Your Money : THE ENVIRONMENT : Your Home Computer Can Help Plot Your Financial Future : Personal finance programs abound. But the machine won’t think for you.

Your long-term investment planning is nil, and you’re thinking of paying a financial planner $100 per hour for help.

But sitting on your desk is enough computing power to launch a moon shot. Maybe you should save money by investing in some of the inexpensive computer software that promises to help you chart your long-term financial future.

Do these programs work? Well, they do provide a broad range of capabilities, such as check-writing, budgeting, financial calculators, retirement planning and investment tracking. But setting up even a modest financial plan on a personal computer--and sticking to it--requires time and dedication.

“People who enjoy tinkering with software will love these programs, but others won’t want to spend a couple of hours per month,” says Kristin Davis, associate editor at Kiplinger’s Personal Finance Magazine.

Developing a long-range financial plan may also require a special program. Unlike most other financial packages, Wealthbuilder from Reality Technologies and Money Magazine ($79.99; DOS or Mac) can help you develop a comprehensive long-term plan instead of focusing on current spending.

You use Wealthbuilder by answering questions that the program employs to rate your ability to take risks, entering information about your current income and investments and then specifying your long-term financial aims.

Wealthbuilder calculates how much you’ll need to save to achieve those goals, and provides advice on the asset classes you should buy for a diversified portfolio. The DOS version goes further by suggesting specific stocks and bonds, which it rates according to historical performance and other criteria.

The program contains a large database of mutual funds, which helps explain why it hogs a full 12 megabytes of disk space. Its comprehensive nature means you’ll spend a good chunk of time entering your data and working through its suggestions.

It’s not the easiest software in the world to use, but it can get you on the road to some serious long-haul investing. You can also get access to a wealth of current investment data on-line for $9.95 per month--or even more elaborate information for another $8 monthly--using an included DOS program called Smart Investor; the program will alert you if, for example, one of your mutual funds is under-performing in its class.

So what can a financial adviser do that this product can’t? “Play golf with you,” says a cocky Mark Goldstein, president of Reality Technologies.

But of course personal financial programs, even ones as powerful as Wealthbuilder, have their limits.

“Software can’t figure out whether your portfolio is doing all right when the economy takes a downturn,” says Lela Jahn, a financial adviser with Jahn, Bayer, & Associates in San Francisco. “It also can’t help you weigh all the values when you’re faced with a decision, like whether you want to have $4,000 per month or retire early at age 58.”

Like tax preparation software, personal finance programs won’t think for you, but they can be useful for getting a better grip on your current expenditures and long-term pecuniary prospects.

The best-known ones are organized around the familiar checkbook metaphor. Managing Your Money ($79.95; DOS and Mac) from MECA and Quicken ($69.95; DOS, Windows, Mac) from Intuit are two of the leading contenders. A competitor called Microsoft Money ($69.95; Windows) was released last year.

With all these programs, you enter your transactions--checks, ATM withdrawals and credit card expenditures--and assign each one an expense category. Over time, you can see how much you’re spending in each area and compare budgeted to actual expenditures.

This may not sound important for long-term planning, but many people in fact don’t have the faintest idea of where their money is going. “If your financial plan isn’t based on real records, then it’s just a pipe dream,” says Scott Cook, president of Intuit.

If you mainly want to track expenses and investments, Microsoft Money is a good option. With its slick Windows interface and coherent graphs and reports, it’s easy to use. Unfortunately, it doesn’t provide much long-term financial planning.

The more money you have, and the more complicated your finances--by marriage, children, real estate, and investments--the more likely you’ll be interested in the grab bag of advanced planning features found in Quicken or Managing Your Money.

Both let you plug numbers into a set of easy-to-use financial calculators that help determine mortgage or other loan payments and how much you need to save for your retirement or college for the kids. Managing Your Money offers a more extensive set of calculations that includes mortgage refinancing, bond yield to maturity and rental property analysis.

Using the calculators is an excellent way to get quick feedback on your financial planning goals. But remember, the results will only be as valid as the assumptions you plug in. “It’s garbage in, garbage out,” says Kiplinger’s Davis. “But you can learn a lot just by punching in a lot of different scenarios.”

Both programs allow you to track investments and update prices via modem. Managing Your Money adds the ability to execute securities trades on line. It also provides an asset allocation tutorial, which helps you think about the best mix of investments for your portfolio, and a tool for assessing life insurance needs and costs.

Quicken, Managing Your Money and Microsoft Money will all export data into the leading tax-preparation packages as well.

If you just want to plan for your retirement, you can buy a package specifically for that purpose. T. Rowe Price, the Baltimore-based investment service, sells its Re tirement Planning Kit (DOS) for only $15.

The program takes a tutorial approach. You answer questions that help you determine the cost of your retirement and how much you need to save to achieve your goals. If you can stand the undisguised plugs for T. Rowe Price funds, this is a good starter package.

Much more comprehensive is Retire ASAP ($99; DOS) by Calypso Software, which lets you enter detailed information about your retirement investments and chart their progress on reports and graphs. The program requires more dedication, but you’ll come out with a very thorough plan.

If you don’t want to buy a product specifically for financial planning, you can always use your spreadsheet. “The difficulty for most people is knowing what formulas to use and how to set up the calculations,” says Richard Scoville, who writes a spreadsheet column for PC World magazine.

The job is easier if you use a spreadsheet template for financial planning available as shareware from a variety of on-line services.

Shareware programs are also worth considering. They’re distributed free; if you like and use the program, you’re expected to send its creator a check. America Online, (703-448-8700) offers about 25,000 shareware packages and an excellent windowing interface that lets you easily search for specific programs using keywords.

A quick search for financial calculators, for example, yielded 14 different programs geared to loan amortization, future value problems and so on. One example: a popular DOS package called SolveIt! (Pine Grove Software; Trenton, N.J.)