Hooking up Surround sound 5.1 speakers with only one audio jack. Help?

[Silicate Wielder]

Okay so I just got some surround sound speakers for free and they have two audio cables and a gaming/stereo switch on them. I thought it meant that it had two input but thats not the case, when I plug one cable into my mom's laptop it dosn't do anything I get the saem "humming" noise I get with them unplugged, I also noticed the power cable its 6 volts and it has an input of 18 volts.
Is it possible to hook these up using only one audio port using a splicer, or should I see about getting a sound card that supports 5.1 Surround?

[Commander Thor]

A 5.1 system should have 3 cables/plugs, not 2. One for the front channels, one for the rear channels, and one for the center/sub channels.

Anyway, it's usually possible to run the system in 2.1 mode by just connecting the front channels(Usually the green plug) into the audio source. But if you want full 5.1 surround, you're going to need a sound card that supports 5.1 audio.