Dan1Dan,
Sounds like you need to set up data driven testing. The easiest way to achieve this will be with groovy scripts and a data source. You can have the groovy scripts manipulate the XML within the request and implant the data as needed. If there is multiple different services being called I find it easiest to use properties and then put the property expansion within the call itself. As the last step, have it verify that the test case passed, log the results of the test run (I typically use a test name in my data source) with a pass or fail and if a fail, log the step and the assertion that failed then have it loop back to the beginning of the steps, set up using the next row from the data source and run that one.