[Tom Lock]

Hi Marcus, I realize this is probably too late to help you with what you were trying to accomplish this on, but I came across your question while searching for an answer to it myself. I have found it here:

https://www.wondertouch.com/tutorials/aharon/ae_to_pi/ae_to_pi_keyframes.htm

skip to “Part 2: Non-Linear Interpolation”

It has the goods you asked for, I hope this still proves useful to you in some way.

-Tom