FileInputStream file = new FileInputStream(
new File(System.getProperty("user.dir") + "\\Data\\ReturnsAndReplacementsEcomm.xlsx"));
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.getSheet("TestData");
int lastRow = sheet.getLastRowNum();
XSSFCell cell = sheet.getRow(lastRow).createCell(lastRow);
cell.setCellValue("ReturnReference");
cell = sheet.getRow(lastRow).createCell(lastRow);
cell.setCellValue(ReturnReference);
file.close();
FileOutputStream outFile = new FileOutputStream(
new File(System.getProperty("user.dir") + "\\Data\\ReturnsAndReplacementsEcomm.xlsx"));
workbook.write(outFile);
outFile.close();