yes, although you will just have a big ugly white box hanging out,
you'll probably just want to set the express up to join your existing network, or hard wire it, if you've got a connection close.
you'll need a 3.5mm male to male (cable with the connector that's on your headphones but on both ends)
or, you can go digital between the express and the speakers,
you'll need a
mini toslink to mini toslink cable.
not sure if you'll hear a difference in the digital, but the digital/analog converter made by b&w is probably a bit better than the one by apple. and it definitely won't hurt.
check to make sure it really has digital in, i just took a quick look at a spec sheet online.
I need to start double checking my Amazon orders.