No easy or cheep way that I know of.
Someone else may know of a way.
The way we work is you send us a feed that is directed to a RR receiver with specific config info. Each feed is unique.
I can think of several that cost $$$$$$.
You can request two feeds & if you intent is to listen to both, you can use Winamp, ScannerLIve, or ScannerForce.
Winamp & ScannerForce will alow you to have multiple instances running so you can listen to both feeds at the same time.
ScannerLive is a feed scanner where several feeds can be scanned as if they where in a scanner.
Info here:
Live Audio Computer Based Applications - The RadioReference Wiki
Computer Based Applications - The RadioReference Wiki