DIAL-A-JOEY

If you let it ring, success will come. That's the way it was for Marvin Rosenberg, 37, a Brooklyn furniture mover whose answering- machine message-a goofy rap about Joey Buttafuoco-is now the theme for a clever 45-second Com- edy Central promo. ''I've been making songs for my machine for 11 years, thinking someone would call,'' Rosenberg says. ''Lo and behold, the prophet came.'' The prophet, Comedy Central producer Bill Price, got Rosenberg's number from some friends and liked what he heard. The two have just finished ''The Salami Song,'' a spot spoofing alleged bomber Mohammed Salameh and the World Trade Center blast. In the first spot, running only on Comedy Central, Rosenberg's catchy ditty plays over images of Buttafuoco, his wife, Mary Jo, and Amy Fisher, with a bouncing ball to help you follow the lyrics. The big finish is a talk-show snippet: Commenting on the three Fisher-Buttafuoco TV movies, Joey says, ''That's comedy central. It's a joke.'' No kidding.