Blend Mecanim in from arbitrary pose

Hi!

I have a character that can go into ragdoll, easy stuff. But now I want him to get up again.
I can just deactivate the physics and reactivate the animator, but then the pose just jumps into the last animation state. But I want him to blend smoothly from his current (arbitrary) pose into a specific animation.

Animator.CrossFade does not work..

How can I achieve that?

Thank you!