Hi @MSCSF
What I meant is that you could switch to Tensorflow or Keras within KNIME 
Please have a look at this previous recent post where I explained how to implement a normalization using Keras within KNIME. It is not exactly the same problem as yours but you could easily adapt it to do the same as what you want to achieve:
How I can de-normalize a predictive value generated using the NN?
Otherwise, yes perhaps somebody else could help you further with your example whilst staying with the RProp MLP learner & Predictor nodes.
Best,
Ael