Like Clint Eastwood and Jackie Chan, Hong Kong star Chow Yun-fatt is a shrewd molder of his screen persona. Starting out in his early 20s as a soap opera heartthrob, Chow quickly took on leading roles in a string of romantic comedies. Then in the mid-1980s, while a box-office champ in east Asia, he changed his image, becoming the stoic moral anchor in John Woo's male-dominated, nihilistic universe. The risky move paid off, broadening Chow's appeal, especially in the West. Now, slightly over 40 and obviously concerned about the future of Hong Kong cinema after 1997, Chow is once again retooling his image, this time for the global market. In his latest vehicle, the lavishly produced Treasure Hunt (directed by Jeff Lau), Chow's a Chinese American graduate student who works undercover for the CIA. He goes to mainland China to prevent the theft of antique treasures and ends up in the fabled Shaolin Temple, the martial-arts mecca (the first time a film crew was allowed on the grounds). The rather convoluted plot, which mixes romance, villainy, and breathtaking kung fu, is mostly an excuse for cross-cultural jokes and sight gags. True to form, Chow juggles the bewildering elements of the various genres with finesse. In transcending the hokey material, he proves himself a genuine star. Film Center, Art Institute, Columbus Drive at Jackson, Saturday, April 15, 4:00, and Sunday, April 16, 6:00, 443-3737.