FCP Effects to Avid

I believe that if I can get just one effect from FCP to Avid I can use that as info for all others. I have Media Composer at work with no effects, and I have FCP and motion at home - so I'm trying to build effects to take into work that will be usable in Avid.

I'm trying to save a Lens Flare in FCP under Render (composite), a Nattress Lens Flare, or even Knoll light factory flare in FCP so that it will have a matte / alpha channel when I import into Avid. I want to use the flare as a transition between clips.

I have tried Apple's own lens flare - with an 'Add' composite mode and then rendering out with the animation codec that has the built in alpha channel. No luck when importing into media composer. The background just shows up as black.

I have tried Nattress and Knoll but from what I have seen you can only apply it to a clip and not a transparent slug which is what I need.

Any ideas on how to do this?