Hello there, did it work?
I must say i'm quite sure that if you connect it via analog outputs you receiver then serves only as an amplifier. If on the other hand it is connected via S/P DIF, then it surely can use one of i guess few of built in processors which make surround output out of stereo signal. Reason for this is pretty simple: processors all work in digital domain (not saying it's 100% fo all cases but in probably 99% cases of todays consumer electronics) and connecting analog signal to it would require A/D conversion, then processor then yet again D/A conversion. Any processing in digital domain introduces some latency to the signal. In this case we have conversion from digital signal to analog two times, once from analog to digital plus processing the signal somewhere in the middle (albeit probably this latency can only be
measured not actually "
detected" by human).
So you option is: connect the card via S/P DIF - i think you can have both connected at the same time, just choose different input on receiever. Use some of the receivers built in processor.
Second option is: try to find if there is some sort of processor in sound card control panel, if so you may get it to output six channel encoded surround signal for the movies and games that natievly only output two front channels.
PS. What receiver do you have? Which model year?
Hope this would help