IIS & problematic DLL identification?

Hi all,

I've got a windows 2000 sp3 server that has a number of "in house" custom coded dll's (none of which I wrote) that are currently running on this web server. Every once in a while, our CPU shoots up to and stays at 100% and our available memory goes way down....which causes the server to stop responding or otherwise show really bad performance. I suspect I know which custom dll is the cause of these problems...but I'm not sure how I can identify it as beeing the culprit for sure (im part of one team that managers the appl's on the webserver in general, and another team supports this suspect dll in question). I've looked in the system logs via the manage computer, but there isn't any information being logged there as to what might be our problem when these performance hits occur.
In the task manager...I've seen the dllhost.exe shoot way up to 890,000k before and it shouldn't get that high.

1. Is there a way for me to track the performance of a particular dll (i.e. how much memory/cpu it's consuming at a particular time)?

2. How can I determine what dll's the dllhost.exe is managing at the time of such spikes in system resource usage?

Thanks in advance!

I don't know details, but the w2k performance monitor should help you isolate the failing processes.