private void Application_SheetChange(object Sh, Range Target)
{
        log.Info("Reached Application_SheetChange....!!!");

        Excel.Worksheet sheet = (Excel.Worksheet)Sh;

        string changedRange = Target.get_Address(Excel.XlReferenceStyle.xlA1);

    var input = Target.Value;

}

// excelRange.Value = contains the specific row and column
// below line inserts data into cell
 excelRange.Value = qrcodescanneddata;
 currentSheet.Cells[insertAtIndex, i] = finalResultString;