Copy appointments from pst calendar to exchange calendar

A user recently purchased a blackberry and I have added them to our BES serve but I just found out that they have been getting there mail delivered to a PST. They have been using this same PST for there calendar. I want to copy all of the appointments off of the pst calendar into the exchange calendar. This seems like it would be easy but I can’t seem to figure it out. The only way I have been able to find that would work is to hold down control and slect each and every appointment and then drag them to the other calendar. What am I missing? Thanks