For days, aides to Virginia Democratic gubernatorial candidate Charles S. Robb had been touting his appearance yesterday at the White House.

Yet when Robb emerged from a meeting with President Reagan to confront a swarm of reporters and photographers he not only downplayed its political significance, but added that he was "disappointed" that the media had been alerted.

"I don't want to take [political] advantage" of the meeting with Reagan, said Robb, explaining that he attended in his role as chairman of the National Conference of Lieutenant Governors.

Robb said that other than "exchanging greetings on the way out," he had no direct conversation with Reagan, who has promised to campaign for his opponent, state Attorney General J. Marshall Coleman.

Coleman and his GOP running mates for lieutenant governor and attorney general had a 30-minute audience with Reagan at the White House on June 19. gAfter that meeting, Coleman, standing near the spot where Robb stood yesterday, announced that Reagan had been "very positive, very supportive" of his candidacy and said "I think we will see the president taking a role in the campaign."

Robb said he was concerened that there had been "any announcement" of his meeting yesterday, which also was attended by 15 other state and local officials.

Nonetheless, with more than half a dozen television camera crews and several dozen reporters poised before him, Robb launched into his oft-told view of the president's economic program, which he generally supports.

One reporter asked Robb if he didn't think the Reagan program would "wreck" the social programs of "your father-in-law," former President Lyndon B. Johnson.

"We've got to look to the needs and challenges of the '80s, no matter how they affect the programs of the '70s and '60s," Robb answered with practiced calm. Many of the needed programs can still be addressed with federal block grants, he added.

But would President Johnson endorse the cuts? the reporter pressed.

"I don't want to get into that," Robb said. "He's not here to make those judgments."