I have an Excel Add-in that has been around for about 6 years. We have
had problems with spreadsheets that were created with older versions. I
would be so beneficial to determine what version they were created
with.

I know that I could set a property on each worksheet created setting a
self-created version number. I had also thought about adding an "About"
on our menu that displayed the version of the add-in.

Has anyone done anything like this? Is there a better way to set a
version for an add-in and the sheets that use it? Is there a more
automated way than to manually set a constant value for the version
within the code? Any input on this would be appreciated..

Thanks PM