And while were on the subject, for NAV, you dont need the .bat files it uses to install. This is what I do in the script to install NAV.
code:
  
USE X: "\\NAVSERVER\VPLOGON"
? "Mapping X: Status=" + @SERROR
SHELL "X:\VP_LOG32 /p=X:"
? "Checking for new version. Result=" + @SERROR