Exporting all usernames

I'm looking for a way to export all the usernames in the windchill system. Ultimately the goal will probably be to import those names into an excel spreadsheet. Any suggestions?

As a side note, (and please forgive me if I misuse terms here), what possibilities are there to access Windchill using VBA. My impression is that because there is no VBA API, my options for accessing data stored in windchill from Excel are limited.

Thanks,

Dan