Ok so with the help of Bill Brit and the support team here at Argentina I finally got it:
On "Local Directory" we fill only one line and just the "Path", leaving "username" and "password" empty.
On System>Setup>QVWebServer>Authentication I use "Login", "Ntlm" and "Alternate login page".
3) Prohibit annonymous
4) Disable "Allow dynamic licence CAL assignment"
With these setting I get promted for user and password and I can enter one of the user and password of the machine QV is installed on.