Is it possible to use a parented locator to affect only the rotation of its child (so that when I translate the locator, the child does not translate)?

Perhaps my question should be more broad. I need to have a character walk around a path that is much in the shape of a banana.

What I'm really doing is recreating the Daft Punk music video "Around the World" for animation class, and need to animate the characters who walk on and around the curved stairs.

What would be the best way to animate an irregular turn? (walking hoping and skipping?) I will note that I am using the Trax editor, which makes path animation useless.

A parented locator (three actually: one for each foot and the hips) worked great when the character was doing a full circle, but now It's a very irregular shape. Any ideas?

I need to begin rendering in 22 hours. Help is most appreciated.

EDIT: In retrospect, this post might have made more sense under the animation category. Sorry.