How to get the 'Spring' easing to end at the correct tween value?

I’ve just started working with the CS4 motion editor, and it is proving to be a distinctly infuriating experience. I want to tween the z-index of a movie clip from -200 (‘out’ of the screen) to 0 with the Spring easing applied, but there’s a problem; the dotted curve showing the ease never moves past the zero line, and only ends up about three quarters of the way towards the z=0 value I want. So effectively, I’m only tweening my clip from z=-200 to z=-60, or thereabouts.

I’m sure there’s a trick I’m missing here. How do I get the tween, with the Spring ease, to finish at the value I’ve specified?