Will I get Surround Sound From MY PS3 Through My PC

I have been reading that since the speakers i purchased dont have a true dolby surround sound decoder, my ps3 wont be able to output true surround sound out of my speakers.

The Speakers I have purchased are Logitech x-540 5.1 surround sound system.

The speakers have an option (Matrix) of producing stereo sound into 5.1 but this isnt true surround. My end goal is to actually have the speakers output as if they had true surround meaning if i got shot up from the back my rear speakers would indicate to me that i was.

My current setup has my PS3 hooked into HDMI?DVI to a 2 port switch that is connected to my PC and Monitor so i can switch in between PC and PS3. The Audio for my PS3 is gained from a RCA into a converter to a 3.5 mm jack placed into the Line-IN so my sound card receives this as sound, which is then output to my headphones also plugged into my Mobo soundcard.

My question is, since the Speakers dont offer spdif or coaxial inputs, but my computer mobo realtek alc888 accepts an spdif input, is it possible then, to connect the line from my PS3 to my computer through spdif, and then have my speakers that will be connected to my PC play the sound as surround?