With CDMA providers, or at least with Qwest, you don't even have to go that far. Type in the above script, select NAM1 (99% of you are going to be using NAM1), then scroll down to Alpha tag, and boom, change it. No need for operator codes or anything.
This has been tested to work with:
Nokia 5170 (and 5170i)
Nokai 5185 (and 5185i)
The "i" usually means that the phone has a retractable antenna.