It was not the usual party for a new assistant secretary in the Education Department.

Among the guests were the secretary of education, U.S. senators, one of the better known former CIA directors (Richard Helms) and the best known former director of National Public Radio (Frank Mankiewicz.)

But then Madeleine C. Will, a longtime activist and lobbyist on behalf of the handicapped, is not the usual assistant secretary for special education and rehabilitative services. She is the wife of the well-known conservative columnist George F. Will. He's a little peeved at her constantly being identified this way, but generally he's taking it in good-natured stride. "I now feel like Denis Thatcher," he said last night. "Content to walk three paces behind."

After Education Secretary Terrel Bell and Madeleine Will had made remarks, George Will, who has taken some flak lately for his role in helping rehearse Ronald Reagan for his 1980 debate against Jimmy Carter, told the group about the numerous papers and documents his wife had brought home to pore over one night.

"She said, 'I have to testify before the Senate tomorrow morning,' " Will said. " 'George, you ought to have a look at my briefing book.' " The guests guffawed. "I decided I'd pass," he said dryly.

Though there was high praise for Madeleine Will at a reception after her swearing-in at the Capitol, few denied that her name may have helped when she was being considered for the presidential appointment.

"I think it probably made them think longer than otherwise about her in the beginning ," said George Will. But, he added, she has been associated with the Maryland Association for Retarded Citizens, and its members are "great lobbyists. She's the Bob Strauss of Annapolis on this issue."

The name "didn't hurt her," said Bell, "but Madeleine Will is qualified in her own right. And, to be frank, I wanted another woman in a presidentially appointed position."

"It should have affected me very little," said Madeleine Will of her name. "I think I have a good record and I'm proud to stand on it."

The Wills have three children, all of whom were present last night. One has Down's syndrome, and Madeleine Will enrolled him in an early intervention program at Georgetown University. "I spent a lot of time learning about the different developmental stages," she said. With other parents of handicapped children, she created a self-contained classroom within a Montgomery County school.

Although Will has no professional training in special education, "I think I've been in the training process," she said. "And it's very important to learn politics firsthand. You can't learn that in a class."

Maryland State Sen. Howard Denis, who worked on a funding bill for deinstitutionalizing the mentally handicapped, called Will "one of the most effective advocates I've come across."

Making appearances at the party were such Senate figures as the Wills' neighbor Charles McC. Mathias (R-Md.), Daniel Patrick Moynihan (D-N.Y.), Paula Hawkins (R-Fla.) and John Danforth (R-Mo.)--the godfather of the Wills' youngest child, Victoria, 2.

And Mankiewicz's connection to the Wills?

"Great baseball fans," said George Will, who belongs in that classification.