sync old calendar to Google

[Druknmonkey]

So my boss had this Sprint Treo 800w and was synching it to his desktop pc before it crashed. He now has a blackberry and uses google sync. He wants to sync the calendar from the treo with google to reclaim all his old calendar info. When i set the phone to sync calendar to google it says i must disable syncing with PC, but when i attempt to do that it says it wants to remove the calendar that is synched with the PC. I NEED all the calendar information on this phone to merge with google without deleting anything. Please HELP!!