How to convert a SIMULINK-model that contains MATLAB-function blocks to Fixed Point with Fixed-Point Tool and range information from simulation data

Hi,

I want to convert a SIMULINK-model to Fixed Point with the help of the Fixed-Point Tool and use range information from simulation data for Fixed Point Fraction length proposal. However my SIMULINK-model contains several MATLAB-function blocks and the SIMULINK help says, that these blocks are not supported by Fixed-Point tool. So the Fixed-Point Tool doesn't propose Fraction length for variables that are used inside the MATLAB-function blocks.

My question is: Is there a general work-flow for converting SIMULINK-models with MATLAB-function blocks to fixed point?

Best Regards, Nico