Hi User999 ,
I don't have a groovy script example for you. I do have some non-scripted ideas that you could work with.
The first is to create multiple data sources and loops within the same test case. For each data source you can identify the target rows to run. Within the data source loop you can run the individual test steps to target. Then when that loop finishes you can then run another data source loop for the next test steps.
The second idea would be to use the Run Test Case test step. The Run Test Case test step runs a test case from your project as a test step. You can find information on this here.