Creating a custom make file and batch file for Simulink Generated C Code

How can I create a custom make file for my code generated from Simulink model ?

I can see, if I edit and change my template make file from Configuration parameter Dialog box, I can get the desired make file, but I want a custom .bat file too, that calls this make file along with other commands.

I have some environment variable to set and run couple of scripts in .bat file, before compilation begins. Based on these outputs from script the code is to be compiled and linked.