Note that when you import CSV in Excel, Excel will try to determine the data type, it will think 14-1 is a date, you may test (manually edit the CSV first) if double-quoting the value (i.e. “14-1”) will make Excel think it is string. If it works, you can customize the ExportCsv class, similar to https://discourse.hkvstore.com/t/phpspreadsheet-and-titles/723/1