Surround Sound PS3 Help

Ok so I want my ps3 to use surround sound.

The system thatI have is oldschool it doesnt have HDMI inputs or anything. Basically the surround sound speakers connect individually to the sub and then from the sub you run the individual cables for each speaker to the DVD player. Now on the DVD player there is an optical port. I was wondering can I run an optical cable from my PS3 to the optical port on the back of my DVD player for it to use surround sound?

(The Video for the PS3 is connected directly to my Plasma via HDMI)

I think you can do that , connect your ps3 to your dvd player via optical cable and then adjust the sound output in the ps3 under settings

Ok well on the DVD player, it just says Optical, and its next to a coaxial audio as well.

No mention of ins or outs.

and the Sub doesnt have anything other than the speakers into it and speakers out.