Poser 7 - Continuous Acceleration!

Hello,

Can someone please tell me how to do continuous acceleration in Poser
7. Meaning a motion starts out slow, then accelerates continuously
until the end of the segment. Every spline option I try to use insists
on easing off the end of the animation so that instead it goes from
slow, to fast, to slow, then end.

I'm from the Lightwave world where this is fundamentally simple.

Please help, this is driving me crazy!

Thanks in advance..
-James