Java programer trying to extend irr

[Browndog]

I have a very small amount of skill in C++ and I don't really want to have to learn to much, however for my project to move forward I really need to extend irr to add a custom gui skin. Can someone explain to me how I create a class that inherits from CGUISkin. I'm really just not sure about what to put in what header files since Java does not have them.