Add tabs to object properties in an mmc

Question

I'm trying to give users at my helpdesk the ability to view and edit Exchange ExtensionAttributes (specifically 2 and 14). Ideally, I would do this by adding a tab in the "Active Directory Users and Computers" mmc snap-in that would have the information on there. I know it's possible to add tabs - the acctinfo.dll in the resource kit does it, for one thing, but I can't find information on how.