code: public static function ASCIICODE($characters)
      {
          if (($characters === null) || ($characters === '')) {
              return Functions::VALUE();
          }
          $characters = Functions::flattenSingleValue($characters);
          if (is_bool($characters)) {
              if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE) {
                  $characters = (int) $characters;
              } else {
                  $characters = ($characters) ? Calculation::getTRUE() : Calculation::getFALSE();
              }
          }
  
          $character = $characters;
          if (mb_strlen($characters, 'UTF-8') > 1) {
              $character = mb_substr($characters, 0, 1, 'UTF-8');
          }
  
          return self::unicodeToOrd($character);
      }
docs: ASCIICODE.
  
  @param string $characters Value
  
  @return int