editing pictures and video clips (keying/masking)

I have just started using CoreMelt TrackX powered by Mocha and like the features for inserting a static image (just a jpeg photo) in a video clip. Im would like to insert a compound clip (video clip) to insert over another video clip. My question it possible to edit a clip using keying and masking in final cut pro x and save that compound clip than import in into another clip? (using coremelt track x??