restoring exchange calendar

Hi,

One of the user lost all of his calendaring events for 2003. I checked all of his archive files but can't find it on there. The good thing is we still have all of it on tape. We use backup exec 8.6 with our exchange 2000 server. I tried doing a test restore and I got a bunch of duplicates events on his calendar. Is there a way to restore all of his calendar events without creating duplicates? If possible, I just want to restore all events in 2003 but I'm not sure if it's even possible to do this with backup exec since I can't even see the date of any of the items when I'm in the calendar folder. Please help!