Copy Biped keyframes


I have to work with biped animations alot, and the majority of my task is to make animations loop.

So today I set out to create a max script to make my life just a little bit better. Ive gotten as far as creating the desired keyframe on the beginning of the timeline, now I only need to copy this keyframe to the last in the timeline.

Only... the bones of the biped object do not have a .pos and .rotation that I can use for this. Can someone point me in the right direction?