hook up front side audio ports to sound card? mobo?
I have an Asus mobo, but my answer has nothing to do with that.
In my setup, the front panel came with a wire that runs along the bottom of the tower towards the back and comes out the back by using up a slot. The ends are the jacks for mic and speaker which end up dangling out the back of the case. At that point they are plugged into the sound card and just like you, I only need the mic so the speaker wire hangs out while my sound cards outputs are occupied by my speaker setup.
I hope that helps but I think if you had a similar setup you probably would've figured that out. Good luck