Vegas help with transitions needed

I’m having a bit of a problem with my transitions in Vegas.

What I want to do is create an animated watermark for my video making that uses the spin transition over and over during the video, showing my personal logo on one side, and then scrolling the name of the video on the other side (this is sort of like what MTV has done with their watermarks). However, the problem is that when I go to actually make this animation, there is a black background that doesn’t seem to want to go away for anything. I want to have this animation without any background (in other words, when the logo spins around in the actual final product, it’ll show black behind the logo when I want it to show the actual video). I need to get this black space gone and make it a transparent background behind this logo. But whatever I try to do does not work (the spin transition options do not give me this option, and I do not know what to search for to find answers to this issue. It’s a very fustrating thing for me).

Is there anything I can do in oder to do what I want to do (I know my explination may be confusing, but I didn’t know anyway else to describe it)?