Similar to the POSTER tool, UCCX has the step, Create URL Document. However we are limited in that there is no free form content entry point (wher we would normally put XML), as in the POSTER tool. Instead we are limited to parameters. We could also use the Get HTTP Contact Info step in UCCX. However here we are limited to a query string. Attempts to use the POST method with parameters are rejected by the lab RESTful engine. Check out doc with screenshots.
I have this problem too.