Calling a function inside s-function level-2

Hello guys,

I'm using s-function level-2 in the Simulink and I need to call a function from s-function. In fact, I have an optimization problem with nonlinear constraints. So I wanted to use "fmincon", but as you know, I have to define nonlinear constraints as a function like "mycons" and I do not know how it can be handled? Would you please help me?

Thanks,

Amir