Certainly not the most suitable to propose a solution to you.
My knowledge about certificates in Excel is limited.
But I would like to support you with these links in your search for a solution.
How to install a code signing certificate for Excel VBA / Macros
https://stackoverflow.com
Hope you find the information that will help you in your project.
I wish you much success in your project
NikolinoDE
I know I don't know anything (Socrates)
@FlorianFey
