Apply Tree Model

I've a tree model, trained on a training set. It sais things like

|  |  |  |  |  t_81012 > -17.939: 1 {1=3862, 0=233}
|  |  |  |  |  t_81012 ≤ -17.939: 0 {1=0, 0=42}

which basically means that the split on t_81012 leads to leaf cell populations as indicated in { ... }

How can I figure out the same information on a new data set - ie., apply the model to a new dataset and see,
how that model then populates leaf cells (rather than just looking at the combined performance vector over
all leafs?)

Thanks for your help, Stefan