Hi,
you can register the test suite that contains your testcases again with a different language. Please check out the example included in the testframework bundle. There the testsuites are registered as following (Tests::RunnerConfiguration):
// register Tests::ApplicationTestSuiteExample in [Color] skin and Default Language
RegisterTestSuite( (new Tests::ApplicationTestSuiteExample).Initialize( [Color], "[Color]", Default, "Default" ) );
// register Tests::ApplicationTestSuiteExample in [Color] skin and German Language
RegisterTestSuite( (new Tests::ApplicationTestSuiteExample).Initialize( [Color], "[Color]", German, "German" ) );