If I understand correctly you're just trying to connect from the sound card into your receiver, right ? Not sure about the "wall" reference... I think that refers to pushing the sound out across an in house network (probably over power wiring) but that's a different format.
Which are you trying to do ?
If you just want sound card out going into your receiver you need to (a) connect 2 of the 4 pins on that digital/analog jack to a coax cable with RCA plug on the other end, and (b) set your card to "digital outputs only" to put the S/PDIF signal onto the jack.
Here's some good blurb about how to do it... the link has lots of posts, this looked like the most knowledgeable one. There seems to be hot debate re: whether a mono "3.5mm to RCA jack" is the way to go, or whether you need a "4 pin 3.5mm to dual RCA jack" cable. The good news is that everything seems to come from Radio Shack
One caveat -- this only seems to work for playing DVD/CD, sounds like the Creative cards won't put game audio out on the S/PDIF interface. Not 100% sure of that though...
"The Audigy/Audigy 2 or any creative SB with the digital output requires a MONO 3.5mm to coax cable (or RCA, same bit different name). The best way to connect this is by getting a 3.5mm MONO to coax converter then plugging a coax or RCA video cable (yellow) from the converter to the Coax input of any reciever (use the yellow not the white or red as coax should be no less than 75ohm for quality reasons).
You must select digital output only from your card options...also if you are using a DVD programme make sure you select SPDIF so your reciever decodes as opposed to the PC, this may require an upgrade with most DVD software players but is well worth it (if you have a good reciever to decode)
I have an Audigy connected to my Sony STRDA5000ES reciever using the above solution, before I was using 5.1 direct (3 x 3.5mm stereo to 6 RCA) and the volume was very low, now it is digital (SPDIF) the volume is unbearably loud where before it was quiet. The recievers blue S-master pro light comes on also when playing DVD from the PC indicating it is recieving a raw signal...hope this helps, I was looking for ages and finally decided to look at the online Audigy manual that clearly shows the configuration for connectivity to external recievers "
http://forum.ecoustics.com/bbs/messages/5/1656.html 
