Asterisk as an automated sip softphone

Found this link which pretty describes what I want to do: voip-info.org/wiki/view/Aste … er+message.

I can get asterisk to register with the SIP server I already have available. But I need the glue in between. All I want this asterisk installation to do is register with the sip server and process call files in the outgoing spool. It sho
uld otherwise be locked down.

I don’t understand how I define the channel between the call file and the SIP
server. Any help?