There is at least one program that you an use that can be controlled via sockets to control a HQCT radio module: CPCTuner!
I know because I wrote it and I also use it as a background program in my own frontend which is build arround socket communication. Let me know if you are willing to use it, then I can send you the socket commands. The software itself is freeware and can be downloaded here: http://users.telenet.be/cpc.
PS Of course you need a HQCT module to get it working.