meta key problem C-M-\

[Marcel Lautenbach]

Hello

hope you folks around this group may help me.
I ran into trouble trying this command:

C-M-\

emacs wont take CTL-ALT-AltGR-ß to get C-M-\

On German keyboards you have the ß. with shift you get ? and with ALT GR 
yout get \. But trying the above command with all three together (CLT, 
ALT and ALT GR) and the ß-key is interpreded als M-\ . But I have to use 
the ALT GR key to get \ .

any idea how to get around this problem?

note: Yes, I know, I could uye M-x indent-region, But I would rather 
like to use the short key combination.

Thankd in advance :-)

Marcel