Hasta La Motion!

So I’m trying to make a composite of an object floating on a little “pad”, and then have my hand reach in and grab it, spin it around a bit, and then place it back on the “pad” to float. (Note: Much like the Unobtainium scene in Avatar)

I have 2 clips, one of just the pad blank, and one of my hand reaching in holding and spinning the rock. The rock is taped to a pen to make it float, and I am trying to key out the pen but am not sure the best way to do it.

I tried using mocha, and followed the entire object with an X-spline track, but I don’t think that was the right thing to do, as I am trying to import it into AE and turn the x-splines into a mask, but don’t think this is possible (or easy at least).

There has to be an easy way to just mask the rock itself, and then mask my hand going in, so that besides the rock and my hand, it is all the background video that is seen.

I’m fairly new to this so if you could be as specific as possible would help! 5 second clip linked to show you what my masking in AE looks like (shit), because I have to keyframe almost every frame as it moves so much. I’ve done it fairly lazily to show you what I am trying to accomplish though.

Any help greatly appreciated.

Link: http://www.youtube.com/watch?v=NfefjNoxPJw