More than a few sniffled yesterday afternoon when a preview of "The Kid From Nowhere," an upcoming NBC movie about the Special Olympics, drew to an emotional close. Its star, real-life Special Olympian Ricky Wittman, sat on the edge of his seat, rubbing his fists together and covering his face as he watched himself on the screen.

"We put such stock in excellence, especially in intellectual excellence," said Sargent Shriver as he introduced the film. "We sometimes forget that those who are not labeled, by us, as brilliant, can still contribute in a spiritual way to the quality of human life."

But before the film's final scene drew applause in the usually silent screening room of the Motion Picture Association of America, and before the reception that Shriver and his wife, Eunice Kennedy Shriver (she is president of Special Olympics, Inc.), helped sponsor to promote it, young Wittman held a press conference.

"Have you flown before?" Eunice Shriver asked the 11-year-old.

"Yes. I like it," answered Wittman, but only after he escorted a reporter to the conference table and held out a chair for her. Later, while telling photographers to please wait to get his picture, he turned to straighten the tie of a nearby businessman.

"My son also swims. You'll meet him at dinner later," Shriver told Wittman, a victim of Down's syndrome who has won gold medals for breaststroke and butterfly in the Special Olympics.

"How fast?"

"You'll have to ask him. But he can't do butterfly."

Wittman began work on the made-for-TV movie in April, as his mother explained it, after Beau Bridges, who plays a special education coach in the movie, visited a few schools and selected him. Aida Wittman, an artist and assistant special-education teacher, said one of Bridges' questions was, "Does Ricky know how to pretend?" One of his schoolteachers helped coach him during the production, and although in the original script he had only eight lines, more were added as he improvised. The finished story, about a woman (played by Susan Saint James) who raises a mentally retarded boy alone and their involvement in the Special Olympics program, is scheduled to air Jan. 4.

About 75 guests attended the reception and preview. Many represented corporations and civic organizations, including Procter & Gamble, GEICO, Coca-Cola, the American Legion and the Council for Exceptional Children. Fred Krause, executive director of the President's Committee on Mental Retardation, said the status of programs for the disabled remains "pretty good. They haven't suffered any budget cuts or reductions. More emphasis has been placed on the private sector but, of course, that's the role of the Kennedy Foundation and the Special Olympics."

Wittman, according to his mother, was paid for his work in the form of a trust fund for his education. But yesterday, he seemed to have other things in mind.

"Mommy! Mommy, let's get some cheese and some wine," he said.

Said Shriver as she led the Wittmans into the party: "Coke for you."