Connecting TV to Dell Subwoofer system?

I have a Dell PC subwoofer system which is connected to my pc and I would like to get the Audio from my TV to play through the Dell speaker system, is there any way to this?
p.s. This is the system I have

the ebay link is dead

Sorry, here is another link, it is the Dell [Altec Lansing A425] system, Nothin can be connected to the sub or satelite speakers so I need a way to simply send my TV’s Audio though the pc I am guessing via the line-in on the soundcard?