Next week, 18-year-old Vicky Foster will give up her job at a McDonald's here and head off to college at Virginia Polytechnic Institute and State University, one of 18,000 undergraduates streaming into the southwest mountain community of Blacksburg.

For Foster, a top scholar and class president of Richmond's Armstrong-Kennedy High who was sought after by schools in several states, it's a dream come true.

For Virginia Tech, Foster represents a welcome success story in its troubled effort to attract black students under a faltering statewide federal desegregation plan that Virginia officials say is currently falling far short of its goals.

Foster, who made three trips to Virginia Tech before deciding to go there, said some other schools "were saying: 'We've got to meet the quota. We need blacks. Come to us. Come to us.' I got it from all over the country." She said she chose Tech for its academic program.

Tech has reported enrolling 182 new black students this fall, fewer than half of the 368 it had set as a goal. At the University of Virginia in Charlottesville, of a reported 3,137 new students, 203 are black. But only 99 of those are from Virginia, while the school had hoped to enroll 207 black Virginians.

"One of the problems we have is that the pool of potential minority applicants that have enrolled in strong academic programs [in high school] is small," said Calvin Jamison, an admissions official at Virginia Tech. "We don't want to create a revolving door situation for bad students. It would be unfair to the student and the university."

Jamison said one promising student from Roanoke turned down a scholarship worth $16,000 over four years at Tech to accept another state school's offer of $48,000.

Virginia is entering the second year of the three-year desegregation effort begun by the administration of Gov. Charles S. Robb after the failure of a 1978 desegregation agreement that John N. Dalton, Robb's predecessor, signed with the federal government. Virginia was one of several Southern states cited by the NAACP Legal Defense and Education Fund in a lawsuit that sought to eliminate the last vestiges of the region's dual system of higher education.

"Remember, this is a three-year plan," said Barry M. Dorsey, associate director of the Virginia Council of Higher Education, the governing body for the colleges and universities in the state. "We'll also count the additional students who enroll in the second quarters and semesters. We're dealing with very preliminary numbers."

Dorsey noted that last year the schools were lagging behind but went on to enroll enough students by the end of the term to gain modest praise for the first time from the U.S. Office of Civil Rights, the Education Department's enforcement arm.

"There has been no other official action since then," said Robert Harvey, director of post secondary education at the rights office regional headquarters in Philadelphia. "We are still awaiting their next report. We would expect good faith efforts to meet the goals." A spokesman for the Legal Defense Fund could not be reached for comment.

Some officials of Virginia's 13 traditionally white four-year schools have acknowledged that efforts to recruit minority students this year are more difficult than last year.

"Methods that have proven effective in recruiting black students in the past did not seem to produce the same results this year," one black admissions official at the University of Virginia told Associated Press last week.

The state's universities have extended application deadlines, established summer tutorial programs and provided additional financial aid to attract minority students. Officials also say they believe enrollment targets will be aided by students entering the state's 25 popular community colleges.

In addition, Virginia Tech's Jamison said the state's public schools this year have formed a new group called the Virginia Admissions Council on Black Concerns to coordinate student recruitment. "We easily see ourselves fighting over the same students," he said.

Another problem for the traditionally white schools is the effect of increased recruiting of minority students on traditionally black schools such as Norfolk State and Virginia State in Petersburg.

Jamison, who said he believed Tech's enrollment goals were unrealistic, said "if we did meet the goals, then it would affect the traditionally black institutions. If we reach the goals by expanding the pool of applicants, that will help everybody."

The desegregation program also requires the state to encourage white students to attend the traditional black schools. Preliminary enrollment statistics from those schools are expected tomorrow.

Jamison faulted the desegregation plan for not counting blacks from out of state who attend Virginia schools. He said that limits the schools' efforts to recruit in nearby areas such as the District of Columbia and Maryland.

The new admissions council has begun a statewide program to encourage counselors, teachers and principals at schools with black students to emphasize academic achievement rather than channeling blacks largely into vocational training.

A recent survey of Virginia's high school students showed that 26 percent of blacks were enrolled in high school academic programs, compared with 43 percent of whites. At the same time, 42 percent of whites went on to college-level courses in Virginia compared with 32 percent of blacks, Jamison said.

Foster said Tech has the programs she wants and isn't too far from home. "They were very serious. They said you come to learn and all the extra things are just that, extra."

Still, there have been problems.

Foster, who lives with her mother and 14-year-old brother in what her mother said is a "low, low, low income" family, is depending on scholarships and student loans to pay her way. Although accepted into the engineering program, she said she had to switch to geophysics because she could not afford to purchase a required personal computer that costs $3,000.

"No way I could afford that," she said.