Need help optimizing my setup

Thinking about buying an Apple TV but I want to make sure I will have the ability to have surround sound. Right now I have

Cable box to TV - HDMI
DVD Player to Receiver (old with no HDMI) - optical audio/S Vid
TV to Receiver - Optical Audio/S Vid

I plan on buying a new receiver, but not right away. I have no more optical ports but was wondering if I connected the ATV to my TV via HDMI would I get surround sound through my receiver using the optical already there?

Thanks