I saved the expressions and tried to load them in PI, but every way I tried crashed PI every time. And I don't have PFTrack or Boujou. I have After Effects 5.5, which I don't use any more, but it seems like a waste of time to have to go and track something in there when it's already tracked in Shake and I'm doing all the compositing in Shake, not to mention that Shake has a better tracker.