need to access project files within jars

I need the maven plugin (and testrunner.bat) to execute test cases in projects where the project file is located within a jar. Our tests will be archived in a maven repository within a jar and we need to be able to run them from within the jar. e.g.:

testrunner.bat foo.jar!/test1-soapui-project.xml

I've tried several variations of this and cannot get it to work. Can we get that feature added?

-tim