If we add that to the HTML_Templates.pm file, and make sure it's in the %tags hash, it would then be available to all the templates as well, including the .cgi programs.

You wouldn't have to edit anything, just make sure to add that routine to the HTML_Templates.pm file for each revision.

I'm still hoping Alex will work in a CUSTOM.pm file, where local subroutines and customizations can be placed, and then included, which will prevent lots of edits down the road

The reason is that it's clumsy enough to paste the user/local variables into the top of the HTML_Templates.pm file each time, to make changes throughout the program as the program gets larger will be more difficult, so that a CUSTOM.pm file and such will be much more important over time.