Hello,

Here is the adaptation of the previous lines of code that works in my
setup (the web page https://www.emacswiki.org/emacs/RegularExpression was helpful):

(require 'autoinsert)
(auto-insert-mode)  ;;; Adds hook to find-files-hook
    (setq auto-insert-directory "~/MEGA/org/my_org-templates/") ;;; Or use custom, *NOTE* Trailing slash important
    (setq auto-insert-query nil) ;;; If you don't want to be prompted before insertion
    (define-auto-insert "\.beamer-fr.org" "my-beamer-fr.org")

Now, supposing that I have to give a talk in French at Aix-en-Provence (very nice
city!), when I open in emacs the new file aix-beamer-fr.org this file
automatically contains the lines defined in my-beamer-fr.org that is
in ~/MEGA/org/my_org-templates/ .

That is certainly trivial for a lot of people in this list (and I
apologize), but maybe it will be helpful for others.

Best wishes,
–
Jo.