VBA - Save new version of file with today's date in the filename

[Benoit]

Hello,

In a current macro that I'm using, I would like to add a feature that when a
file is opened, it saves a backup version of the file in a specific directory
and add today's date to the filename.

In example, my macro will open file "TEST.XLS" and make many changes into
it. Before the changes are done, I want the macro to safe the file in the
"C:\backup" directory and the filename should be "TEST (YYYY-MM-DD).XLS".

Also, if I open the file twince in the same day, I want the macro to
overwrite the file with the latest version.

Thanks!!!