Well, you can sort of fake it by adding the glass effect to the frame itself. Here is a skin of mine with crappy gfx, but it'll give you an idea of what I'm talking about
:
http://members.dslextreme.com/users/...ster/frame.png
I just altered the title font color to fake it looking like it was under the "glass." This is probably going to be your best bet for getting that glass layer look on the PL window. I know it can't cover the entire window, but it's better than missing that glass look completely.