Steve Cohen, "The Millionaire's Magician" still continues his exclusive weekend performances at the Waldorf Astoria in New York, but he has decided to add a new show to his repetoire. Opening tomorrow night, also at the Waldorf Astoria, Miracles at Midnight will be held only once per month, at midnight and is billed as the world's most exclusive magic show. Only 20 seats will be sold for each performance at a cost of $250. In Miracles at Midnight, Cohen combines favorites from his long-running show, Chamber Magic, along with a dozen miracles that have previously been reserved for his private performances. Cohen has performed magic for Warren Buffett, Barry Diller, David Rockefeller, Michael Bloomberg, Jack Welch, Martha Stewart, Stephen Sondheim and the Queen of Morocco.