iPhone Calendar wiped out after sync with an empty Outlook 2003 Calendar

I need some help.

iPhone Calendar wiped out after sync with an empty Outlook 2003 Calendar.

Unable to restore from backup as my iPhone was backed-up before I realised my calendar info was gone.

I found an old backup file in my old disk but was unable to move the old calendar data to the empty outlook after restore. It just keep wiping out after I sync.

Thanks.