protected function _WhereFromOrderBy($Part, $Comment, $Op = '') {
      if (!$Op || $Op == '=')
         $Op = ($Part[1] == 'desc' ? '>' : '<').$Op;
      elseif ($Op == '==')
         $Op = '=';
      
      $Expr = $Part[0].' '.$Op;
      if (preg_match('/c\.(\w*\b)/', $Part[0], $Matches))
         $Field = $Matches[1];
      else
         $Field = $Part[0];
      $Value = GetValue($Field, $Comment);
      if (!$Value)
         $Value = 0;

      return array($Expr, $Value);
   }