Reading the manual, it doesn't appear you can use both analog 4 or 6 channel audio as well as have independent mic/line in. There are only 3 jacks on the thing, two of them go to speakers in 4 channel, the other gets used for whatever, and all 3 are used in 6-channel mode.
In plain stereo mode, only the green jack is used, the pink and blue jacks are for mic-in and line-in.
You can use 6-channel mode AND have a front panel mic-in jack using the headers on the board, but you can't make a separate line-in function, and you can't make the pink jack turn to line-in while using 4-channel.
You can order the digital adapter if you have digital speakers and that will free the other jacks. The adapter is what has the RCA connector on it for SPDIF output. Actually, I read that again more fully, and it doesn't appear you can even get an RCA (coax) jack output, only optical. But I did find that the EP-SPD0C seems to support coax.
http://www.epox.nl/english/products/motherboard/accessoiries.htm
Just one minor thing I noticed on that site:
Asus has never been known for quality in general.
Uh...huh.