Passwords can be tricky:
  .
Sometimes it works if you Log-In first 
Sometimes copying cookie to HTTrack directory works
Sometimes you must include an URL with the Password
  (like: <http://username:password@www.mdconsult.com>)
  .
You may need to Catch URL:  
  1. Browse to Login Page in Netscape
  2. Highlisght URL, Copy (Ctrl-C)
  3. Paste (Ctrl-V) in Win-HTTrack Add URL >>Capture URL  
  4. Change Browser Proxy 
       (Netscape Edit>>Preferences>>Advanced>>Proxy)
  5. Click "Login" (see HTTrack message) 
  6. Start Mirror