it's easily doable and you don't need gimmicks like url matching to do it.
post the popup code and i can help specifically, but in general, there's only one snag to doing this easily: you need to call popup.close() from the opening page.
you can do an onsubmit event on your popup's form that calls a function on opener that
1. popup.close()es the data entry form
2. reloads itself (location.href=location.href)
maybe something like this:
on the opening page:
and on the popup page:
<form onsubmit="opener.finish()" ... >