Nice, i'll wait then! this is great for multiple sites with only one domain (not really the ajenti V focus). like having http://mydomain.com/munin and http://mydomain.com/owncloud 

hm, don't think its about that... its more about adding an alias and forget the root like this:

location /munin/ {
alias /var/cache/munin/www/;
}

is there any gui tool to add this per website? if i add this lines to the website custom configuration, it will work as http://domain/munin/ but will also work as http://domain/ (root) no intended to! sorry for the lack of knowledge, don't know if i made me understand well