Touch Diamond CDMA help

[diablo900900]

I have recently purchased a touch diamond from alltel, however i receive poor cell reception at my house. to get around this problem in the past i was able to go into my old samsung phone's service programming and turn PRL off. this would allow my device to be roaming but connect with the best receptive tower around my house giving me the strongest signal. (i went from 0 service to 3/5 bars but roaming which doesnt cost me anything.)

I was wondering if anyone knew how to change the PRL or if anyone could offer any idea's into how i would get better service.
thanks