[Cisco] vpnclient will honor a saved user name and password, but overwrites the config file and erases them. So you can also do something like this:

#!/bin/sh 
cd $profiledir 
cp myprofile.saved.pcf myprofile.pcf 
vpnclient myprofile

Put your username and password in the saved file:

Username=myname 
UserPassword=mypass  

This is for Linux but it should work the same.