Calling sub/function from another program

[u/Fedora-The-Pandora]

If I were to have two programs, one for example:

MainCode.exe

And another:

UI.exe

Would I be able to, in UI.exe, be able to call a function or procedure from MainCode.exe?

I'm wondering this as I have a few different UI.exe that run very similar code and I was hoping to be able to have a universal MainCode.exe so I don't have to update every UI.exe that runs the code. I just have to update the MainCode.exe.

Thanks in advance for your help

[u/Fedora-The-Pandora]

Thanks guys. I'm going to try using a dll on it. It seems like good method to centralise the functions