"M*A*S*H's" Trapper John is to testify before the House Banking Committee this morning. Not many people know that the affable actor Wayne Rogers, of TV series and IBM commercials fame, is also a successful businessman whose extensive investments include part ownership of a bank in San Jose and another in North Carolina. Rogers recently wrote Rep. Fernand J. St Germain expressing his concern about proposed legislation to gut the Glass-Steagall Act, a Depression-era law aimed at ensuring the safety of banks by barring them from becoming involved in the securities business. St Germain, seeing the obvious publicity benefits, responded by inviting Rogers to testify.

Rogers said yesterday that he was surprised by the invitation and is aware that he wouldn't have been asked, "obviously, if I were an itinerant farmer, but I'm happy to be used." A Princeton graduate, Rogers had a healthy distrust of business managers when he moved to Hollywood and so decided to do his own investing. He even helped some of his actor friends, such as Peter Falk, James Caan and the late Jack Webb, with their investments. Rogers expects to tell the committee of his concern that the proposed reform of the Glass-Steagall Act will be bad for banks, getting them into the risky securities business, which is not insured by the federal government.

Out and About

Wild man rocker Frank Zappa, currently performing at the Warner Theatre, is concerned about citizenship and voting, so he asked the League of Women Voters here to supervise voter registration tables at his concerts. He had already joined the league in conducting successful voter registration drives at recent concerts in New York City and Albany, but the league won't be working his concerts here. Leona Rumsey, president of the league's Washington chapter, says the group's main reason for rejecting Zappa's request was that the Maryland and Virginia chapters wouldn't be able to participate, but she added, "We don't know about his politics ... once we step over too far in being partisan, there's trouble." A recent newspaper article quoted Zappa as being critical of Republican presidential candidate Pat Robertson. Now if only he had criticized all the candidates ...

More on America's film festival in Moscow next month. Not only will the Soviets get their first opportunity to see Ronald Reagan in "Kings Row," they'll also be able to view 30 other films there for the first time. Among them will be "The Wizard of Oz," "The Empire Strikes Back" (now they'll understand Reagan's reference to "the evil empire"), "Romancing the Stone," "Shampoo," "The Killing Fields," "An Officer and a Gentleman," "Cool Hand Luke" and "Roxanne." Among the American actors attending the festival will be Richard Gere, Carrie Fisher, Daryl Hannah, Marlee Matlin (the "Children of a Lesser God" Oscar winner also will visit a Soviet school for the deaf), Matt Dillon and Susan Sarandon. Tri-Star Pictures says the Soviets have granted permission for director Walter Hill to film scenes for his "Red Heat" in Red Square. It stars Arnold Schwarzenegger as a Soviet cop and Jim Belushi as a Chicago cop. Glasnost works in such unusual ways ...