CDMA Carrier ID?

[gudujarlson2]

On a CDMA Windows Mobile phone, how does one determine the home carrier (e.g. Sprint, Verizon)? By home carrier I mean the carrier that the phone owner has a contract with, not the carrier that owns the current cell tower. On GSM phones I can use the first 6 digits of the IMSI (MCC+MNC) to determine the home carrier. On CDMA phones this does work, because even though CDMA phones supply a IMSI, the same MNC values are used by Verizon and Sprint. On CDMA Blackberry phones I can use the home SID, but I have not found any function in RIL or TAPI that supplies the SID. I have searched the registry and a number of phones, but have not found a reliable value that determines the home carrier.

Any help would be greatly appreciated.