How do I obtain generalized weights of the parameters while modeling with ANN?

While developing ANN model to predict Y from 7 independent variables, I want to calculate the generalized weight of the each independent variable with response (plz see the attached fig). I know how to do in in R, but I need to execute this in Matlab. I appreciate your help and feedback.

[Greg Heath]

What do you mean by a generalized weight?

...The fraction of average target variance that can be attributed to each variable?

I think that requires a backward search.