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): 

#+BEGIN_SRC 
(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")
#+END_SRC

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.