meta translation

[harven]

Hello,
I want to translate some key with a meta modifier into another
e.g. M-m into ` or S-tab into M-tab. The following does not work

(keyboard-translate ?\M-m ?`)

Nor does 

(keyboard-translate ?\S-\t ?\M-\t)

(global-set-key (kbd "M-m") (lambda () (interactive)(insert "`")))
works but unfortunatly it does not play well with the various input-methods
to get accented letters. As far as I understand, this is because 
M-m is in fact a combination of two characters. From the emacs manual

   ...Emacs translates each Meta character into a pair of characters
   starting with <ESC>. When you type the character `M-a' in a key
   sequence, Emacs replaces it with `<ESC> a'...

Is there a workaround to solve this problem ?