http://httpd.apache.org/docs/misc/rewriteguide.html
sieht so aus:-)
Canonical Hostnames
Description:
...
Solution:
RewriteCond %{HTTP_HOST} !^fully.qualified.domain.name [NC]
RewriteCond %{HTTP_HOST} !^$
RewriteCond %{SERVER_PORT} !^80$
RewriteRule ^/(.*) http://fully.qualified.domain.name:%{SERVER_PORT}/$1 [L,R]
RewriteCond %{HTTP_HOST} !^fully.qualified.domain.name [NC]
RewriteCond %{HTTP_HOST} !^$
RewriteRule ^/(.*) http://fully.qualified.domain.name/$1 [L,R]