title: emacs create key modifier
body: <p>I am using emacs on mac os. 
  I would like to map a modifier (Meta, Control,...) to a simple key.
  Basically this is what I need : <code>(global-set-key (kbd "a") 'hyper)</code>
  Here a is just the a key, no Control-a or whatever, just "a" alone whithout modifier.
  I want "a" to become hyper for example but I can't find a solution for this.</p>
  
  <p>Someone have a clue ?</p>