Audit Calendar Appts in Public Folders

[DJCopa]

Hello There.

I was wondering if there is a way to see who edits a specific Public Folder Calendar Appt.? Public Folders are setup on an Exchange 2003 Server.
Calendars in question require a team of 20 to have Publishing Editor rights, as changes need to be made at different times to various appts. However, we would like to know who made the last change at any given time.

Thanks in advance for any help.