How create DLL using only C/C++ types?

Library Compiler Application create DLL with MatLab type mwArray (for C++, and mxArray for C):

extern LIB_libcfit_CPP_API void MW_CALL_CONV cfit2(int nargout, mwArray& u, const mwArray& x);

My trading robot (MQL4/5 language of www.metaquates.net) can't use functions from DLL with such types. So I create function for robot (working in Metatrader 4):

__declspec(dllexport) int __cdecl Cfit(double* px, int N)
{
  mwArray mwx(N, 1, mxDOUBLE_CLASS);
  mwx.SetData(px, N);

  mwArray u;

  cfit2(1, u, mwx);
  double result[1];
  u.GetData(result, 1);
  return static_cast<int>(result[0]);
}
Could you show a simple example (steps) how to create (using MatLab and/or Visual Studio) DLL for Metatrader?