loading a DLL file to my wxFormbuilder GUI - C++

[Langdon Cobb]

Hello

I am working with simulation software written in C++ and I need some help.

I created a DLL file and linked it to my original code.
now I need to write a functions inside this DLL, but the variables and these functions are already identified in the original code.
my question is if it's possible to write in the DLL file what is already defined in the code, and how!

I'm not an expert and I hope I made my point clear :/

Thank you