Rosalynn Carter came to a luncheon of 800 Jewish women yesterday and didn't miss the opportunity to give the administration side of the U.N. vote snafu.

"The U.N. vote was unfortunate because it was contrary to United States policy," the first lady conceded in remarks to delegates to the international biennial convention of B'nai B'rith Women at the Washington Hilton Hotel. b

Mrs. Carter, a shrewd and experienced campaigner for her husband, was scheduled to make some remarks yesterday about her visit a year ago to the B'nai B'rith Women Children's Home in Israel.

But she took the initiative at the beginning by telling the delegates that she wanted to give her thoughts on what "I know is on your minds."

An audible groan came from the luncheon audience at Mrs. Carter's reference to the United States vote in support of a U.N. resolution condemning Israeli settlement policy in occupied Arab lands.

With vigorous hand motions for emphasis, Mrs. Carter told the delegates: "One man in this country is responsible for the peace treaty between Egypt and Israel -- one man. And that man is Jimmy Carter . . . Jimmy Carter makes the foreign policy and he will continue to do it. Jimmy Carter and no one else."

She emphasized there has been no change in the administration's commitment to an undivided Jerusalem and continued access to holy places.

Mrs. Carter was received with a show of obvious personal warmth from the delegates, who only two days earlier had heard Sen. Edward Kennedy attack the Carter administration's "appalling betrayal of Israel" in the vote at the United Nations.

Before Kennedy's speech, the delegates -- representing 150,000 members around the world and a sizable voting bloc in the United States -- passed a toughly worded resolution expressing "continued dismay at the Carter administration's explanation of why the United States voted on the side of Israel's enemies" in the United Nations.

The resolution went on the question the "direction and consistency" of American policy on Israel and to call on the president for a "plain, unambiguous clarification" of that policy.