Basically, we have a scene of a character holding a mirror. Instead of her reflection in the mirror, I wanted to show different scenes. Normally for this kind of thing, I would just make a master overlay frame in Premiere with a hole cut out in the mirror, making it transparent, and overlaying it over the footage I want to show through only the mirror. However, the stupid water dish near the mirror is animated- as well as light bouncing off the figure and and background because of a lit candle- and I thought it would look weird to halt all the moving light animation in this scene all of a sudden. So I thought instead, I would do a "green screen" of just the surface of the mirror, and then skew the footage as I need and put it in the mirror.
I made the mirror's surface in Photoshop and made it, effectively, a bright green, since that color isn't found in this scene. However, I feel like I am crossing wires here, because I tried using it as an image matte. But that doesn't work, because the mirror then loses the transparency around it, so now I've got a green circle that plays footage, but you can't see the original background behind it anymore ( ie. the woman, the water dish, etc. ) I think I am supposed to be doing something different, like instead, taking the footage that is supposed to appear in the mirror and altering it and making it supposed to play just in the bright green areas of the scene ( which would be the stupid mirror

I'm attaching an image of what the scene looks like, so anyone who is willing to help out my fool self might get a better idea of what I'm talking about.
Thanks everyone.
<img src="http://www.second-element.com/mirror.jpg">