57.4.9 Non-ASCII Characters on the Keyboard
If your keyboard has keys that send non-ASCII
characters, such as accented letters, rebinding these keys
must be done by using a vector like this1:
(global-set-key [?char] 'some-function)
Type C-q followed by the key you want to bind, to insert char.
Since this puts a non-ASCII character in the .emacs,
you should specify a coding system for that file that supports the
character in question. See Init Syntax.
Warning: if you change the keyboard encoding, or change
between multibyte and unibyte mode, or anything that would alter which
code C-q would insert for that character, you'll need to edit
the Lisp expression accordingly, to use the character code generated
by C-q in the new mode.