Jimmy Carter was back at the White House waiting for her to join him for the weekly luncheon date. But Rosalynn Carter was off yesterday carrying out one of her husband's mission, representing him at the 50th anniversary celebration of the Inter-American Commission of Women, at the Pan American Union.

"I want to congratulate the commission on its work on women's rights," she said at one point, departing from her prepared text, "because women's rights are human rights.

She was interrupted by applause when, speaking in Spanish, she told the Spanish-speaking audience that "the participation of women in the development process is of vital importance for the communities of the hemisphere if we are going to achieve the goals of equality, development and peace."

The President has his say as well. In a message carried by Rosalynn, he urged that the anniversary be used not only to reflect on the importance of continuing efforts to advance the status of women in the hemisphere "but also to renew our commitment to ensuring equal rights for women in our own country."

Other on the program were Ambassador Alfred A. Rattray, president of the Permanent Council of the Organization of American States; Licendiada Gabriela Touchard Lopez of Bolivia, and OAS Secretary General Alejandro Orfila.

The commission was founded at the 6th International Conference of American States in Havana in 1928, and was the first official intergovernmental body created specially to work toward the political and civil rights of women.

Until then, only women in the United States had gained suffrage (1920). Beginning with Ecuador in 1929, voting rights were achieved by women in the other nations of hemisphere, ending with Paraguay in 1961.