Unable to find IR Code for power on/off using cox...

Question

I am unable to locate a 4 digit code to use the power on/off using my Cox Cable remote control unit. The Setup Function on the remote does not find one and I have tried many codes for Sylvania/Emerson/Magnavox and Funai, none so far work. Any help on finding the proper code to be able to turn my Sylvania TV off, using the Cox remote will be appreciated.