When the Reagan White House nominated B. Sam Hart for the U.S. Civil Rights Commission and William M. Bell for the Equal Employment Opportunity Commission, Maudine Cooper, vice president of the National Urban League's Washington operations, quickly organized the opposition.

After deciding the nominees were what she called "bad news," Cooper announced the League's disapproval--the first time the League had opposed black nominees for federal jobs--rallied other organizations that were waffling and called the White House to find out why it had selected those men. The nominations were withdrawn.

That's pretty heady stuff. This week Cooper, a 41-year-old lawyer, decided to give up that kind of agenda and exposure to become director of the city's largely invisible and greatly beleaguered Office of Human Rights.

"I have some feelings about how confident I am, how smart I am, how efficient, effective I think I am. It is a time to test those notions. Now I am about to test them in another form," said Cooper.

"She is solution-oriented--I need solutions," said Mayor Marion Barry, who fired her predecessor, Anita Shelton, Monday.

If confirmed by the City Council, Cooper starts next month, and yesterday her strong voice and precise gestures reaffirmed her confident words.

Sitting in her corner office, which looks toward the District Building on Pennsylvania Avenue, the slender woman whose brown eyes have a probing look talked about being "antsy" after 10 years in her job, the need to rekindle her legal skills, the opportunity to have a larger staff and budget.

Even though Cooper can cite some victories that she and the League have been part of--the hard-won battle for the extension of the Voting Rights Act, for example--she said she needs more immediate feedback.

"It's a little hard to measure your accomplishments when you are at the national level," she said. "At the national level, complainants are numbers; in the city office complainants have names. At the national level it's how many have been filed, how many have been adjudicated. In that city office it's who are they, where are there, which employers are there."

In Washington, when a news correspondent goes from the network to the local, when a deputy assistant secretary starts a consulting firm, it raises questions about gaining and losing power.

Cooper has thought about that:

"We all have our egos. It is hard to give up that national image, whatever that might be, to accept something that concerns only the Metro section, rather than the national news. So you think about that. I decided that it was something I ought to do. I didn't think whether it was up, down or aside."

Cooper has lived in Washington since 1958, when she came to study business administration at Howard University. Her parents, Willie and Mary Rice, grew up in Mississippi and later settled in St. Paul, Minn. Her father has been a railroad porter since the mid-1940s and her mother has worked as a housekeeper. Cooper, an only child, spent her early years in Greenville, Miss., and joined her parents in St. Paul when she was 9. "I was 16 when I finished high school and I wanted to marry the church pianist," she recalled. Her mother persuaded her to try college.

During her sophomore year at Howard, she married, a union that lasted 10 years. Without being smug or denigrating, she attributes some of her success to being single. Cooper, who has one child, a 22-year-old daughter, Maria, lives in Alexandria but plans to move into the District.

"This kind of job, for the Urban League, was not the kind of job that would provide for a strong sense of family. I am gone almost two to three times a month, someplace, to present the Urban League point of view, to talk about some key issue. It just doesn't lend itself to family solidarity."

The activism of her years at Howard, which stretched from 1958 to 1971, when she earned her law degree, did touch her. "The first time we marched because the dorms weren't clean. While I was in law school, I was arrested at a sit-in at the Office of Economic Opportunity. The issue was a grant program to prepare minorities for law school that had been promised to Howard but we thought was going to a white school," she said.

After two years in various legal and legislative jobs, Cooper joined the Urban League in November 1973 and has served in several key posts. When Vernon Jordan announced her promotion to vice president in 1980, she broke out in tears. Recalling that she was the League's second woman to become vice president, Jordan said yesterday, "she helped to usher us into the 20th century in terms of women's involvement in the movement." His successor, John Jacobs, said, "She has been valuable, innovative and committed."

Along with her lobbying, she organized six roundtable discussions this spring between organizations that represent minorities and the current Democratic presidential candidates. All the candidates attended.

Had she been overlooked for promotion at the League?

"Nothing's gone wrong," she said emphatically. "How many times can you relate to congressmen, relate to the Hill, relate to the White House? After a while the faces change, the issues remain the same, the responses remain the same. You get to a point where you want to record your response: 'What you are about to do will be devastating to poor minorities in this country.' They, the decision-makers, need another face to look at as well."