Courage Mountain is a heap of good, clean very clean fun, chronicling the further adventures of storybook heroine Heidi as she blooms into a young woman. At the turn of the century, Heidi (Juliette Caton) leaves her grandfather (Jan Rubes) and her boyfriend, Peter (Charlie Sheen, who looks like a well-fed suburban punk rocker and sounds like a kid from Topanga Canyon), for boarding school in Italy, where she will learn to ''provide for herself.'' But her formal education is cut short when the Italian Army takes over her school, forcing the more fortunate girls to go home to their families, and the less fortunate, whose families are unreachable, to go into an orphanage. A grimmer place full of more pathetic waifs would be hard to find. Signor Bonelli, the smarmy director of the institution, is running a clandestine child labor operation. When Heidi and four friends escape, carrying this wicked secret, the evil Bonelli tries to track them down and do away with them.
Heading home to Switzerland ''crossing the Alps in their street shoes,'' as their former headmistress (Leslie Caron) puts it the girls are captured by Bonelli and saved by Peter, who hurtles wildly through the air on skis to rescue them like some kind of Batman of the Alps.
Most of the acting is, well, broad, but it's good enough to carry a less-than-poetic script. Least convincing is Charlie Sheen, the only actor in the movie with an American accent, and unfortunately the one with some of the silliest lines. ''Uh, I have to go,'' he says woodenly when he's first confronted with Heidi as a beautiful grown-up woman.
Caton's Heidi is a pleasing heroine: smart, sympathetic, and strong. For girls under 12, her story probably will be very appealing. B