well, this isn't EXACTLY what you're asking for, but here goes:
in the area you want the popup to be, create a shortcut that opens the popup. kinda like the start menu. you click the start menu, and it opens up right there. not necessarily because it CAN'T open up anywhere else, but that's where it was opened from, so it stays there. does that make sense? the theme I'm using now has one like that for my frequently used programs, so I know it works, I'm just not sure if I'm explaining it well.