If this isnt what your looking for please excuse me I am nowhere near the video editor you guys are but I think I might be able to help
If I understand you right, you are trying to have that image with transparency in photoshop?
<img src="http://i11.photobucket.com/albums/a164/burningleaves09/Untitled-2copy.gif">
If that was what you were looking to do then ill go step by step
Load the image in photoshop
Cut the section you want to work on
Open a new document make sure the background is set to transparent
Paste the image
Trim out what you dont want
Save as .Gif make sure the box is checked for Transparent in the save menu
If this has nothing to do with what you were asking then im sorry





