Pronto does IR, TCPIP or RS232, not RF.

I don't know about the Nuvo, but the standard approach for CBus is to use TCPIP. You have to study the communication protocols (published by CBus) and then write some scripts to send the appropriate commands (and, if you wish, to receive status feedback). The exact messages to be sent depend on how you have set up your CBus, whether it is wired or wireless, etc. There are a number of threads specifically about Pronto and CBus in the CBus forums.