code: private static function translateFormula(array $from, array $to, $formula, $fromSeparator, $toSeparator)
      {
          //    Convert any Excel function names to the required language
          if (self::$localeLanguage !== 'en_us') {
              $inBraces = false;
              //    If there is the possibility of braces within a quoted string, then we don't treat those as matrix indicators
              if (strpos($formula, '"') !== false) {
                  //    So instead we skip replacing in any quoted strings by only replacing in every other array element after we've exploded
                  //        the formula
                  $temp = explode('"', $formula);
                  $i = false;
                  foreach ($temp as &$value) {
                      //    Only count/replace in alternating array entries
                      if ($i = !$i) {
                          $value = preg_replace($from, $to, $value);
                          $value = self::translateSeparator($fromSeparator, $toSeparator, $value, $inBraces);
                      }
                  }
                  unset($value);
                  //    Then rebuild the formula string
                  $formula = implode('"', $temp);
              } else {
                  //    If there's no quoted strings, then we do a simple count/replace
                  $formula = preg_replace($from, $to, $formula);
                  $formula = self::translateSeparator($fromSeparator, $toSeparator, $formula, $inBraces);
              }
          }
  
          return $formula;
      }
docs: @param string[] $from
  @param string[] $to
  @param string $formula
  @param string $fromSeparator
  @param string $toSeparator
  
  @return string