How to pass arguments when calling lsqnonlin from C++ with mexCallMATLAB?

I want to run lsqnonlin which is a matlab optimization function from C++. From matlab it is called as follows:

      lsqnonlin(@(x)funcHandle(x,var1,var2,..),x_initial,[],[],options);

From metlab c++ API I understood that mexCallMATLAB is the function I should use to call matlab and get the output

      int mexCallMATLAB(int nlhs, mxArray *plhs[], int nrhs,mxArray *prhs[],
      const char *functionName);

how do I pass all the arguments to mexCallMATLAB - {funcHandle,var1,var2,..,x_initial,[],[],options}, especially the function handle? I found this "mclCreateSimpleFunctionHandle" function, but I'm not sure how to use it? I have a mexFunction implementation of the funcHandle, and created a mexw64 version of it, I think I should use that somehow..

Thanks

[James Tursa]

Are you passing the result of @(x)funcHandle(x,var1,var2,...) into the mex function? I.e., are you creating the anonymous function handle at the m-file level and then passing that into the mex routine and wondering how to call mexCallMATLAB with this?

Or are you creating var1, var2, etc inside the mex function, and then wondering how to create the function handle inside the mex routine to use to pass to lsqnonlin via mexCallMATLAB?