At that distance you'll want to consider the digital connection for high quality sound, as an analog signal would degrade to a noticable degree. Of course you can minimize the degredation by using $50 high end RCA cables for the analog connection, but that kind of defeats the purpose now doesn't it?
<font color=blue>You're posting in a forum with class. It may be third class, but it's still class!</font color=blue>
You need to connect the audigy's 3.5mm line out plug to your stereo's aux input plugs. The below two part numbers from cablewholesale.com will do that. They also make a custom cables at good prices. I keep my noisy T-bird system in a different room from the one with my desk and monitor/keyboard/etc, and I got all the cables from these guys.