I'm trying connect to Airport Express from a different subnet on our office network

Hello everyone,

We have a subnet that's dedicated to our AV needs which is different than the one used by our PCs. This is to make sure the AV devices do not overwhelm the PC network. I have two Airport Expresses configured on the AV subnet and trying to connect to them via iTunes on the PC subnet, but the Speaker button doesn't appear on the buttom of my iTunes window and I cannot find anywhere to manually enter IP addresses for the AEs. Thanks for any insights!

Sean