i'm pretty sure you can do it quite easily with the physics engine (download the lite-c workshop on the main lite-c page, coz one of them tells you how to use the physics for a rolling ball).

alternatively, click the "quaternions" link in my signature, which will also help you with that. there is a small example further down in the thread, and the quaternion functions will be updated quite soon but the ones that are there work very well (except quat_for_ang, for now).

hope this helps,

julz