I think you guys although being truly helpful may have glossed over the fact that I cant hardwire my airport into my router, the wireless router is in another room.
No sir, we have not glossed over that fact at all. "Hard wiring" it would be ideal but is not required to make AirTunes streaming work. When I wrote about "connecting to your network" it was meant in a wireless sense.
What is necessary is to configure the Express to "join" your existing wireless network as I explained. "Creating a network" would be possible if it were hard wired to your router.
It is not possible unless your router is an AirPort Base Station - then you could take advantage of the "extend a network" capability of AirPort Base Stations.
As I wrote earlier:
... Your AirPort can create a new network, extend an existing network (Apple Base Stations only), or join an existing network (any kind).
If your laptop can already connect to your existing network in every room you do not need a "stronger signal" nor would it convey any benefit, nor would it have any effect whatsoever upon your ability to stream AirTunes.