u can connect it to the motherboard via builtin headphone/line-out jacks, but thats going to be an analog output and only stereo (2 channel). The most this amplifier can do for you is upmix it to 4 channel Dolby Prologic-2.
for full 5.1 or 7.1 output, u have to send a digital signal from a soundcard, which can then be fully decoded by the amplifier into DTS or DD. The digital signal is optical or coaxial.
u can also use the soundcard's internal decoder and attach the outgoing L/R, Rear, Center and subwoofer cables from soundcard into the respective analog inputs on the amplifier. i will have to confirm if the amp has these jacks.
i will get back to u with the model no. I've been using it for 2 years now.