title: Leading Zero Issue when exporting excel from grid
body: <p>In the below code i am export excel from grid when export the leading zeros get deleted.I want to maintain the leading zero.Please help me to solve the issue.</p>
  
  <pre><code>HtmlForm form = new HtmlForm();
  Response.Clear();
  Response.Buffer = true;
  Response.Charset = "";
  Response.AddHeader("content-disposition", string.Format("attachment;filename={0}", "Supply/DemandReport.xls"));
  Response.ContentType = "application/ms-excel";
  
  StringWriter sw = new StringWriter();
  HtmlTextWriter hw = new HtmlTextWriter(sw);
  gdSupplyorDemand.AllowPaging = false;
  gdSupplyorDemand.HeaderStyle.ForeColor = System.Drawing.Color.Black;
  
  form.Attributes["runat"] = "server";
  form.Controls.Add(gdSupplyorDemand);
  this.Controls.Add(form);
  form.RenderControl(hw);
  
  string style = @"&lt;style&gt; .textmode { mso-number-form at:\@;}&lt;/style&gt;";
  Response.Write(style);
  Response.Output.Write(sw.ToString());
  Response.Flush();
  Response.End();
  </code></pre>