PG 8.2 change Letter Sort Order

Hello Group,

I have a Database for German Text using UTF-8 and want to change the sort order of Letters.

Creation Database:
initdb -E UTF-8 --locale=de_DE.UTF-8 --lc-collate=de_DE.UTF-8 --lc-ctype=de_DE.UTF-8 -D DBPath

The Sort set with --lc-collate=de_DE.UTF-8 was not the right Sort Order ( ß=>ä=>aa=>äb). I need a sort where ß==ss and ä ==ae.
Is there an over Value for lc_collate who changes the Sort Order? (de_DE.ISO8859-1,C,POSIX dosent change it correctly
Or can i change the Sort Orders in Postgresqls Config Files? I havent found the correct ones

OS:
Solaris 10
PG 8.2

Thanks for Help

Jens