Hi,
The property transfer is definately the option I use, although I sometimes find it easier to use an HTTP Request TestStep instead of a REST TestStep, as the HTTP one allows you to replace the entire URL string - see :
http://community.smartbear.com/t5/SoapUI-Open-Source/Parametrizing-Endpoint-Resource-Method-and-paramter-values-in/m-p/102919#M18026
This post goes beyond your needs, but discusses / links to information regarding how to set HTTP TestStep endpoints (beware there is an issue with the editor forcing the URL to lower case, reported as a bug).
Hope this helps,
Cheers,
Rupert