Adding Airport Express To Linksys

Well I have this stupid Linksys wireless system and I just bought a Airport Express to stream music around my house. I need to add the Airport Express to my linksys network, but the Airport Express Client won't notice my Linksys Network.(I can not at this time replace my network.) How do I get the Airport Express software to recognize my Linksys system?

I set up the so called network with a Linksys broadband router I don't know if this makes a difference and I only use it for wireless internet. I am using Windows XP, Please help!!

so youre using windows, did you set this network up using airport express setup assistant?

I am looking to add the Airport Express to my Linksys network. The guy at the Apple Store said I could do this!