Nowadays, it is not difficult to find the correct spelling of such a popular song. Search "M'en revenant de la jolie Rochelle", and from the resulting 2350 sites inspect several of those that are completely in French, and not designed by foreign teachers. The corresponding rule applies to most other languages.

At the risk of provoking another national conflict, I may mention that most sites seem to place the origin of that song in France, La Rochelle being a city near the Atlantic coast of France. Let's call it "Atlantic" ;-)

Accents on capital letters are omitted in modern French, but if you want to use them, it should be À la santé ....

A votre santé! To your Santa!