How to train neural network using newff with a custom loss function?

I want to train a neural network (f) with input A and output B. I want to train it with the loss function between g(f(A)) and C where g is a pre-trained neural network. C is another data set. How can I use a custom loss function? Are there any other functions other than newff? Below is my code (very simple)

net = newff(minmax(A),[10,51],{'logsig','purelin','trainlm'});

net.trainparam.goal = 0;

net.trainparam.lr = 0.01;

net = train(net, A, B);

Answer 1

[Hiro Yoshino]

Which version are you using?

Looks like there is no such a function.

This might be a help: https://www.mathworks.com/matlabcentral/answers/64319-neural-network-how-to-use-a-custom-performance-function