Older P4, Dell C600 as HTPC?

So I just bought a new Samsung 37 inch 720 HDTV. Love it, had it about 4 months.

My current DVD player is very old, will not play DIVX or even DVD RWs. Just DVDs. Its junk I know.

So for the hell of it, I hooked up my old Dell C600, VGA to VGA, to the new TV.

It works extremely well except for the damn audio. The only place to plug in the external audio on the laptop is the headphone jack. So I have a Male-Male audio cable that runs from the laptop mic out, to the audio in on the TV.

I get sound except there is a lot of sound interference type of stuff going on, buzzing and static.

When I play a dvd movie from the laptop the video is great and the sound is even good except during the quiet parts of the movie, theres that damn buzzing and static.

Is this simply poor audio card quality on the laptops part? This is what I gather.

Is there anything else I can try and do to improve the audio? This laptop would same me lots of time and money instead of building a HTPC!

Thanks!