Hello everyone!

I am wondering if any of you know if I can add a wireless keyless entry keypad to my truck such as the TP100 TouchPad entry system (found on ebay). The truck is a 2003 f250 7.3. The truck has an after market alarm system by Clifford on it. I've seen where people have added a keyless entry to their trucks in the past but they all seem to have the factory keyless remotes.