NEW YORK OVERNIGHT : Schwarzenegger ‘Like a Father’ to His Nephew

SCHWARZENEGGER ‘RAISING’ A NEPHEW: It’s a script right out of Arnold Schwarzenegger’s hit movie “Twins.” Only this is real life.

For several years, the pumping iron actor has quietly been helping to raise his late brother’s illegitimate son and has now provided him with a job and shelter in L.A.

“He’s like a father to him,” claims Wendy Leigh, author of the new unauthorized biography “Arnold.”

In “Twins,” Schwarzenegger tracks down a long-lost brother and helps him.

Now, Schwarzenegger is doing the same thing for Patrick Knapp, who was fathered by Arnold’s brother, Meinhard, in 1968 in Munich, West Germany, writes Leigh.

The two brothers had not talked in years. Arnold even refused to attend Meinhard’s funeral in 1971. But he later wrote to Patrick’s mother, Erika Knapp, and offered help. Eventually, Erika asked for assistance, and Arnold provided it in the way of cash and tuition payments for Patrick’s schooling.

In the late 1980s, Patrick finally paid his uncle a visit in California and ended up staying, writes Leigh. He was even in Arnold and Maria Shriver’s wedding on April 26, 1986. Today, he lives in a house owned by his uncle in Venice and trains in a nearby World Gym outlet.

Leigh says that as kids the Schwarzenegger brothers were often pitted against each other by their domineering father, Gustav, an Austrian policeman who joined the Nazi party on July 4, 1938. According to Leigh, Gustav took “delight” in humiliating the loser--which, surprisingly, was often Arnold.

DE NIRO HELPS HONOR WILLI: It was one of those typically New York afternoon get-togethers with everyone eyeing everyone else and the “dahlings” and “how-are-yous” flowing like diet soda.

Toukie Smith had scored a coup of sorts by persuading her steady beau, the usually reticent Robert De Niro, to come out for a benefit fashion show Sunday afternoon on Willi Smith Day 1990 in honor of the designer who died of AIDS.

Toukie is Willi’s sister, and she has dedicated part of her life toward keeping her brother’s name alive by holding fashion shows for charity. In all, four local charities benefited from the event, which also introduced new young designers.

Among the celebs were Mayor David N. Dinkins, Ashford & Simpson, Lou Diamond Phillips, clean-shaven director Martin Scorsese, Chris Walken, Gregory Hines and Sherry Bronfman, who split from Seagram’s heir, Edgar Jr., in December.

Valerie Simpson and Walken took to the runway to model a few duds. There also was a raffle, some dancing and a buffet. And over in the corner, away from the crowd, was beautiful Drena De Niro spinning records as the party’s DJ. Drena is Bobby’s teen-age daughter; her mother is Dianne Abbott, De Niro’s only wife. They’re divorced.

HERE AND THERE: Natasha Richardson, star of Cinecom’s “The Handmaid’s Tale,” will be a maid no longer, come summer. She and producer Robert Fox will walk down the aisle in London in June. . . . Producer Fran Weissler dropped this tidbit the other day: Negotiations are under way for Kathleen Turner’s play “Cat on a Hot Tin Roof” to eventually make it to the little screen via ABC-TV.