Hi Babymaker....
I've been using this little popup manager for some time, and it does everything you want and some
Check it out at
http://www.vixne.com/products.html
To make the demo easier to understand, you only need to look at the Popup Windows and Combination area's - that's all that's relevant to what you are looking for.
It can be used as either a popup exchange script, or just for your own popup management (that's what I use it for)
Hope that helps....