Sharing variables, Union data type, between Level 2 S functions

Hi,

I created a union data stucture (global) in a header file. Both the MEX files can access the header file

They are two C functions, of type void sfunc(void) and void sfunc1(void). The first one access the union data structure and assigns the value and the second C functions reads the value from the union data structure. The two C functions will be two separate MEX S-Functions

Since Union is a data type not recognized by Simulink. I am trying with Level 2 S functions.

Below is the image for representation

I have looked into this link about creating a dll file, but I am not sure how to create a dll file and attach it to simulink.

Is there any other way to do this?

Thank you