I'm going to try explain better:
- My root site is a Wordpress multisite in the path "/var/www/sites/multisite/" (what is a symbolic link to "/var/www/wordpress") with a "wp-config.php" file.
- My QA site is in the path "/var/www/sites/question2answer".
I have created a site in my multisite administrations sites with the name "questions", but it can't manage de QA, because as I told, the Wordpress integration not run (the lines give me errors).
Then, I have create a new virtual host in my Apache http Server named "questions.mydomain.com", that redirect to QA path ("/var/www/sites/question2answer").
When I try manage the "questions" subdomain site with Wordpress, it go to the QA path, and I can manage it.
It's not elegant, but it's running.
I think that it's not relationed with my problem, but you know the complete scenario now, as you want.