writing data to excel file

See more:

C#

C#4.0

i have gridview data that i write in the excel file. its function is as,

protected void btnExportToExcel_Click(object sender, EventArgs e)
    {
        try
        {
            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", "EmployeeAttendance.xls"));
            Response.ContentType = "application/ms-excel";
            StringWriter sw = new StringWriter();
            HtmlTextWriter htw = new HtmlTextWriter(sw);

            gvDisplayRecords.RenderControl(htw);
            Response.Write(sw.ToString());
            Response.End();
        }
        catch (Exception ex)
        {
            lblEmpAttError.Text = "" + ex.Message;
        }
    }

now i want to write single line under this gridview data. for the total days employee present and absent how can i write it.