For me the simplest solution would be extending some how org.eclipse.jubula.rc.common.tester.TabbedPanTester since this class already is dealing with the tab title.
I tried with the help of the Functional Testing Extension Manual to implement my own Tester Class TabbedPaneCustTester extending TabbedPanTester.
Unfortunately without success.
I have to admit that I'm new to the whole RCP/Eclipse/Plugin/Feature thema.
I created a Plugin Projcet containing a TookitProvider extending abstractToolkitProvider, an Activator and some i18n properties.
In the same project I put the ComponentConfiguration.xml file. See attachment.
I'm not sure with the declaration of the extensions for the Plugin. What do I have to declare there. See attachment.
I created the feature and placed the previously created Plugin to be packaged in the feature. See attachment.
My target platform references the jubula installation and the development/extension-toolkit-rc.zip. The features org.eclipse.jubula.feature and org.eclipse.rcp and many more are selected.
The best place to look for help on this would be in the jubula rc-dev archives or even the jubula-dev archives. There have been a lot of threads there where we've helped out with extensions. If you don't find any answer in the threads, start a new one in the jubula rc-dev mailing list.
Bear in mind as well that you can also have the team implement it for you if you want to do it that way .