Yeah, you'll need an audio splitter and audio cable to do that on hardware level:
Splitter:
http://www.triplebit.com/images/Splitter-1.jpg
Cable:
http://home.earthlink.net/~mac-minidisc/Mac-MD/Images/cable.jpg
Put the splitter into you audio-out of your soundcard (where your speaker cable is now), then in one of the two splitter connections you put the speaker cable, in the other you put the cable you bought. Then put the other end of the cable you bought into your mic input (where you microphone cable would be normally. Done.
If you would like to use you micropohe too at the same moment you could buy another splitter so you can connect the cable an mic at the same time
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The parts are very cheap, the cable is probally the most expensive. Ask for the shortest cable they have because the longer the cable the higher the price.
As for the technical stuff, ask for this:
- 3.5 millimeter stereo audio splitter
- 3.5 millimeter male to male audio cable (can be either mono or stereo, microphone is mono anyway). Most stores the sell computer or audio parts will have it.
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