Parameters of the objective function for the nonlinear fitting routine

I want to conduct a nonlinear least square fitting using MKL. However, I don't know how I can introduce some additional parameters for the objective function. Does anybody have some ideas?

This is the introduction of the routine: https://software.intel.com/en-us/node/471086

This is one example code for the routine: https://software.intel.com/en-us/node/471540

How can I past some parameters for the objective function (the f(x) function in the introduction or the extendet_powell() function in the example code)? Thanks very much.