Loop a physX based animation

[Narad13]

I'm working on a physX based animation for a lottery client. Because this is going into an interactive experience I need a portion of the video (with the balls moving around) to be looped. So ideally something like:
-f 0-100 balls spin up
-f 100-300 balls move around (looped)
-f 300-400 balls settle back down

I have no idea how to loop an animation that is based on physX. Is this even possible? If so any help would be appreciated!