Q: Setting up Airport Express with exisiting non apple wireless

Hi there

I wonder if you can help

I have just purchased a apple express V2 to allow me to use airtunes through the stereo in my lounge.

I have plugged the airport express into my stereo and created an new wirless netowrk and it works from my iphone, great... however

I now have two wireless networks one with airtunes and one with the internet not ideal as I have to keep swapping them over for music or internet on my phone / laptop. So I plugged the express into my current BT router and got the internet working on the express.

However In order to do this I had to move my BT router from the hall to the lounge so it was in wired range to plug into the express, in moving the router I have  reduced the wirless range in the rest of the house.

Is it possible to leave the BT router where it was in the hall and wirelessly add the airport extreme to the exisiting BT network so I can still get good wirelss signal around the house but also play airtunes to the stereo?

Sorry if this doesnt make sense!

Thanks

Ben