Using the built in cell phone without On-Star in your H2

[Peter]

Is there a way to use the cell phone that is integrated into the H2 for calling people other than On-Star? I did a search before posting this and found a few posts where people say they use On-Star to connect to personal numbers but have to go through On-Star operator. I'm interested in using the cell phone without going through On-Star. Is there somewhere I can connect a keypad to dial? I carry a Sony-Ericsson T68i cell phone in my pocket but I was hoping to benefit from the longer range and hands-free of the phone built into the H2. Anyone here know a way to achive this?

Thanks,
Peter