I'm not sure that I completely understand the issue. However, by creating a calculated field or placing the event field on the filter shelf should be able to easily return user IDs. Would you be able to post screen shots of what you're trying to do to help me better understand, as I think I'm a little off?
Hi Tracy, thanks for your response. I have actually uncovered the real source of the problem, and it nullifies my concern here. I'll post a new thread with the new problem to avoid any confusion.