RCA jacks inside the case

I am putting togeather a computer for someone and the case I am using has jacks on the front of the case for a mic and a headset. The wires that go into the case to hook up these two jacks have RCA plugs on the end. How am I supposed to connect RCA plugs inside the case?

This seems very odd to me beacuse I have never seen a place to hook up RCA plugs inside the case. Can anyone help?

Oh and here is the link to the case on newegg......

http://www.newegg.com/app/viewProdu...-144-026&depa=0

and here is the product number.....

N82E16811144026

RCA Jacks look like those 3 yellow, white and red connectors that go into the back of your tv. Y'see, what the case manufacturer did was just make it so you could have your audio jacks up front. Basically, your case just has 2 extension cables running from the sound in back to the sound in front. This sucks. I would much rather have them plug into soundcard or motherboard headers. That being said, if all he wants is an easily accessible port to plug his headphones into, that is definitely a surer method than hoping the user has motherboard headers for sound.