Sending video to Apple TV and audio to Air Express

Hi,
I use several Apple TV devices to play movie files stored on my PC on various TVs throughout the house.

I also use several Apple Air Express devices connected to my HIFI systems around the house to play ITunes music.

How do I send the movie audio to an apple air express whilst watching the movie from the Apple TV. It appears my Server APP will only allow me to select one receiving device at a time.

That's true. You can only send video to a single AirPlay receiver. You can send just audio to multiple receivers though.

Can I ask why you want to send video one way and audio another?

I have a outdoor detached patio from the main house where an "apple TV" is plugged into a wall mounted TV. Sound quality is very poor via this TV when playing movies.
Also in the patio I have self powered HIFI spreakers installed high up from the rafters where the audio is received via an "Airport Express" device.
I installed these systems with WIFI connections to avoid exposed cabling since I have solid walls.
Hence, I would like to play a movie and the sound via my HIFI speakers.

I have tried connecting the RCA Audio Out of the TV to the HIFI speakers but becuase of the cabling distance the sound is very poor and not a pure when connected directly to the AE. Also doing this,it forces me to plug and unplug cables each time I want to watch a movie. It requires me to use a high ladder.

Ok that's a tricky setup.....

What do you mean by "my server app"?

I have the "Air Video" APP on my iPhone.
It allows me to connect to my PC that is running a progam that acts like a server.
From this server program, I can play all types of movie files from my computer to any "apple TV" and the server will convert this file type to that format that is sutiable for itunes and Apple TV. It saves me from converting hundred of movie files into a format that Itunes will play.
So just like the iPhone "remote" app, I can use my iPhone to select and play any movies I have on harddrives.
Love the power and integration capability of Apple products

Ive looked, but can't find anything that will fulfill your exact requirement.

But I can suggest a solution. You can replace the tv to speaker cabling with a Bluetooth sender / receiver combo. That way the audio quality will be maintained and the wireless requirement is met

thanks. Your suggestion seems to be the best option. Pity though, its another cost.