I'm not sure I understand your question, but I'll try to help anyway. I looked up the specs on your Audigy 2 soundcard and found that is has a S/PDIF digital output that will accept a coaxial cable. A coaxial cable has the common RCA-type connector at each end.
The problem I think you have is that your Panasonic home theater system doesn't have a digital input. I looked around for Panasonic Home Theater Systems sold at Costco and found the SC-HT700 model, which doesn't have a digital input.
I'm afraid you're out of luck.