[quagga]

There is no way to "mark" a certain portion of a model, you can only select the model id and preview it. The only parameters that can be set are the rotation and the zoom. I suppose that you could however create some sort of semi-transparent red square text draw over each portion of the body and name them accordingly, then display which ever one you want to highlight over a certain portion of the skin. That would be the only way I could think of to highlight/mark a part of the model.