Decoding Dolby Digital issue

Hello,

I am having an issue trying to decode the Dolby Digital 5.1 Signal coming from my XBOX-360 going to my PCI Express Sound Blaster X-Fi Titanium Fatal1ty Professional Series sound card.

With that said, I have done extensive research online through Creative forums, and by calling Creative techincal support all of which come back negative for a X-Fi Creative sound card with a built in decoder.

Can anyone tell me if there is a software program that can decode this incoming signal? if so an inexpensive one, or even better free. If there is no software decoder that is worth a darn, is there an external decoder that does not double as an Amplifier (just decodes the signal and then can be trasfered to the Sound Blaster card)?

On a side note, I am using Windows 7 32-bit OS.

Thank you for any input,

-String