Daniel Stern, one of the ''City Slickers'' in the movie that is doing so well at the box office, says he had no trouble riding in the movie. ''I had had one horrible experience on a horse, but I showed up and had no fear,'' he said. ''The horse will do what you say. It's a leap of faith.''
''City Slickers'' is about three city boys who play ranch hands for two weeks. As they do, they talk male talk, which has led some critics to say that the film is for men more than women.
''I don't know that it's limited in that way,'' said Stern. ''I think women like men who talk about their feelings, and in this movie, they do.''
Stern got the role when Rick Moranis dropped out. ''They were in a desperate frame of mind,'' said Stern. ''It was a great opportunity to get a job like this.''
Jack Palance is in the film. ''He doesn't converse the way I do,'' said Stern. ''Ask him a question, and he gets back to you a day later. But he's a very artistic guy.''
Stern was one of the burglars in ''Home Alone.'' Naturally, a sequel is in the works, and Stern will take part. ''We begin filming in November,'' he said. ''The burglars get out of jail, catch the kid, tie him up in the basement and torture him,' he said, then added, ''Just kidding.''
There is no script, not yet, but that doesn't bother Stern. ''I trust the writer and the producer,'' he said.
Stern was raised in Washington where he did some work with the Montgomery County Players, then went to New York at the age of 17. He doesn't know why he became an actor. ''I think it's because I like to tell stories,'' he said.
''The Phantom of the Opera'' will now run through Sept. 28 at the Kennedy Center in Washington. The engagement was extended because of ''popular demand.'' Call 202 467 4619.
Also extended, for the same reason, is ''Forever Plaid,'' the musical playing at Ford's Theater in Washington. ''Forever Plaid'' presents a '50s song group, now deceased, whose members have returned to Earth for ''one last concert.'' The show will now run through July 28.
''Shore Leave 13,'' the 13th annual ''Star Trek'' convention, will be held July 12 and 14 at the Marriot Hunt Valley Inn. Among the personalities expected to appear are George Takei, Mr. Sulu of the original TV series and the five feature films, and Michael Dorn, Lt. Worf of ''Star Trek: The Next Generation,'' syndicated sequel to the original TV series.
The convention will include guest talks, autograph sessions, dealer rooms, videos, panel discussions, a costume gala, an art-auction show and a blood drive, to be held in cooperation with the Red Cross. Call 821-5563 for information.