I have not done this in forever but maybe I can help a little bit.
In your pc control panel or under connections find your bluetooth. Open it up and you should be able to set up a virual com port there. I did not have built in blue tooth so I am not sure of the procedure.
When I tried to connect it will ask for your pass key on the pc and the treo.
you might check out FAQ here or on the palm.com
This is a link for a sprint 650
http://kb.palm.com/SRVS/CGI-BIN/WEBC...m_External2001