Crystal Reports - how to set ExportFormatType MSExcel as .XSLX insted of .XSL

Hello,
we are using separate Crystal Report service IIS application pool to show reports from Origam in various file formats - PDF, MSExcel, MSWord. Is there a way how to set default report format for MS office files to .XLSX and .DOCX instead of obsolete .XSL and .DOC?
Thank you.