GetGroups( $Server, $GroupType, < $List | \@List | \%List > [, $Prefix ] )
    This will, if successful, populate the @List array with the names of the 
    user groups that match the group type $GroupType.  If $Prefix is passed in
    then only groups with names beginning with $Prefix (case insensitive) will
    be stored into the array.
    $Server is either:
      - The name of the machine the accounts reside on in either "\\\server" or "//server" format.
      - The name of a domain as in "Accounting" where the user accounts reside.
      - An empty string ("") which returns the user accounts for the local machine.