Ok, I understand what you mean. But I don't need a subdomain to be a separate website, the settings / limits should be as for the parent website, I just need it to point it to a directory inside the website directory, so if I say, for example wiki.somedomain, I would like wiki to point to wiki directory inside the directory for somedomain. Co-domain however can only forward the url from wiki.somedomain to somedomain/wiki. So there is no way to just make it point to a directory and keeping parent settings, but a website needs to be created.
An I correct in my understanding now?
Thanks for your help.