I think what you're wanting is possible. I'd have to spend some time looking into it as I don't know off the top of my head.
If you haven't do so already, download my Solid Edge Spy program as it will help you figure out how to do it. In a nutshell, you'll probably have to enumerate through the assembly's occurrences and look for the holes.
I'll try to get you an example in a couple of days.
Posted by: Jason Newell Post date: 3/1/2006 9:35:03 PM