I remember reading an article about flashing a CDMA device to another CDMA carrier. Which was very interesting and relatively similar. Except both devices were of the same technology. The carrier even provided a flashing service for those looking to port their CDMA phones, but this practice was discontinued as GSM began dominating the market and people began to slowly move away from CMDA handsets.
However, there is no method that could make a GSM device perform on CMDA frequencies. GSM uses IMEI as its mobile identifier while CMDA uses ESN. Ideally, the carrier would also have to also approve whichever electronic serial number would be using their network. Which they would never do if that phone was from another provider, even if it were CMDA. But if the device utilizes SIM cards then there is no possible way to provision it to run on a CMDA network. This is just simply not possible, as these are two entirely different types of hardware.
If the device was built by the manufacturer to support both standards then it would be entirely possible. As the case with Blackberry Storm. Otherwise it just can not be done.