First, welcome to the forum!
You could bypass the receiver all together and hook the speaker system directly to the TV. If the TV has a digital audio output, you can connect that to the Logitech system because it will take either an optical digital input or a coax digital input.
Are you set on hooking it up through your receiver? If so, please let us know which receiver you have so that we can look up the connections that can be made with it.