How can generate new initial values in workspace from simulink to reset a subsystem?

I have a simulink file that is initialized with a m-file. I define the m-file as the initialization callback and I don't have problem to initialize the simulink for the first time. But, I need to reset a subsystem of my simulink file to the values that differ from the initial values. To comput the reset values, I need to run the m-file in workspace. How can I run a m-file in workspace from simulink to use its output as the reset value?