>>You can use the Shell.Application automation object - it's Windows collection
>>includes all running instances of InternetExplorer.Application, and you can
>>examine each instance's LocationURL property to find the right one.
>
>Thank you Ed, your advice opened the door to an area of programming possibilities unknown to me. It made me solve my IE instance problem in just a few lines.
>
>Looking for some documentation of the Shell object I found SHELLCC.CHM, though it is toilsome to surf through the HTML help pages. Having a diagram of the Shell object model (like the Outlook object model in VBAOUTL9.CHM) would make things a lot easier. Do you know where such a thing could be found?
>


Sorry; it's in the MSDN Library in the section on Reusing Web Browser Technology; it's a huge file called INET.CHM; about 110MB.

"VBScript Programmer's Reference" from Wrox Press has the IE4 and IE5 object models outlined, and Wrox has a couple of books covering the IE object model from different perspectives, including a detailed look at the XMLDOM.