Web Forms :: Export A Big Dataset To Excel Via Web?

Actually I have a SQL query that a user exports to excel in our web server. I did it in c# with Visual Studio 2003 (.Net v1.1): I get the data from a SQL server into a Dataset, then with this method I create the XLS file:

private void ExportAsExcelFile ( DataSet dtExport )
{
Response.Clear() ;
Response.ContentType = "application/vnd.ms-excel";
Response.ContentEncoding = System.Text.Encoding.UTF8 ;
Response.Charset = string.Empty ;
Response.AddHeader ( "Content-Disposition", "attachment;filename=data.xls" ) ;
System.IO.StringWriter objStringWriter = new StringWriter () ;
System.Web.UI.HtmlTextWriter objHtmlTextWriter = new System.Web.UI.HtmlTextWriter(objStringWriter) ;
DataGrid objDatagrid = new DataGrid () ;
objDatagrid.DataSource = dtExport ;
objDatagrid.DataBind () ;
objDatagrid.RenderControl ( objHtmlTextWriter ) ;
Response.Write (objStringWriter.ToString()) ;
Response.End () ;
}

Well, this works when the SQL query has 10.000 rows and so on. But now the query has more than 200.000 rows, and I´m getting a TimeOut Error trying to export the data. I read about generate this big files with a Store Procedure and the SQL Commad: BCP [URL], but I tryed and it fails. I have no permissions to execute this command. Is there any other way to export this SQL data to Excel via a ASPX page?