LIBSVM question

I'm using the LIBSVM package for training the SVM model. I'm using DAG for classification as mentioned here. Details of which part of the code to be replaced are given here.

During testing, I've set of classes I want to test for. This is only a subset of classes for which I've trained the model. How do I incorportate this info into the code posted? I've the the class subset in a vector of integers.

Thanks!