private function writeBIFF8CellRangeAddressFixed($range)
    {
        $explodes = explode(':', $range);

        // extract first cell, e.g. 'A1'
        $firstCell = $explodes[0];

        // extract last cell, e.g. 'B6'
        if (count($explodes) == 1) {
            $lastCell = $firstCell;
        } else {
            $lastCell = $explodes[1];
        }

        $firstCellCoordinates = Coordinate::coordinateFromString($firstCell); // e.g. [0, 1]
        $lastCellCoordinates = Coordinate::coordinateFromString($lastCell); // e.g. [1, 6]

        return pack('vvvv', $firstCellCoordinates[1] - 1, $lastCellCoordinates[1] - 1, Coordinate::columnIndexFromString($firstCellCoordinates[0]) - 1, Coordinate::columnIndexFromString($lastCellCoordinates[0]) - 1);
    }