How to use alpha mask layer with a morphing object? (using a clip from author "Phantomatic")

Hi,
I have just downloaded the “Black Sphere Deform” video-template (from Phantomatic), including a “Alpha” clip. Now I’m trying to use this clip in After Effects to cut out the object from its dark background and to re-export it as an alpha-channel clip. Is this even possible? And how to get to this?
I hope you guys can help me out. Thanks in advance!

Best, Jens

Hi. I hope this helps. It´s a very very simple and short tutorial that explains how to use “alpha matte tracking”, which is what I guess you need for your project.
Link: https://vimeo.com/21534566
Good Luck!