Using lookup table simultaneously with matlab function

Hi. I am looking at an application where in my simulink model, I am using a MATLAB function which is required to give an optimal value for a variable. For finding that optimal value, say it goes from 0 to 1, I need to evaluate a cost function which I evaluate using a lookup table. How can I call the lookup table at each iteration to calculate the cost function? The interpolated value from the lookup table depends on the variable I am trying to obtain as output.

Or, is there an alternative where I can define the lookup table as a MATLAB script and use it in the MATLAB function? I tried to use ScatteredInterpolant but came to know that it is not supported in Simulink. So, I was not able to find a straight-forward way to evaluate the cost function.