EdelingF
I've tried to use http://wiki.contribs.org/Web_Application_Redirect_Tutorial, but it disables the possibility to use the server-manager.
The Howto as written does work. What do you mean by disables server-manager.
It sounds like you have done something wrong or inappropriate.
Did you follow all the instructions carefully and ensure that both custom templates are present
eg
/etc/e-smith/templates/etc/httpd/conf/httpd.conf/92joomla
and
/etc/e-smith/templates/etc/httpd/conf/httpd.conf/80OptDomainJoomla