radGrid export Unicode problem

[Sofiene]

hi, 
when I export my radGrid which contain French character in column title , titles appears in chine character in excel result . 

This is my export config and event code .

Thank’s 

public void ConfigureExport()
  {
      try
      {


          GridPJ.ExportSettings.FileName = getExcelFileName((CImport)Session["CImport"]);
          GridPJ.ExportSettings.IgnorePaging = true;
          GridPJ.ExportSettings.OpenInNewWindow = true;

          GridPJ.ExportSettings.ExportOnlyData = true;
          GridPJ.DataBind();
          foreach (GridColumn col in GridPJ.MasterTableView.RenderColumns)
          {
              col.Visible = true;
              col.Display = true;

          }

          GridPJ.Rebind();
      }
      catch (Exception e)
      {

      }



  }

  protected void GridPJ_ItemCommand(object source, GridCommandEventArgs e)
  {
      if (e.CommandName == Telerik.Web.UI.RadGrid.ExportToExcelCommandName ||
         e.CommandName == Telerik.Web.UI.RadGrid.ExportToPdfCommandName ||
         e.CommandName == Telerik.Web.UI.RadGrid.ExportToCsvCommandName)
              {
                  ConfigureExport();
              }
   }