c#excelをテンプレートからエクスポート

private void Bind()
    {
        //    
        string TempletFileName = Server.MapPath("template.xls");
        //    
        string ReportFileName = Server.MapPath("out.xls");

        string strTempletFile = Path.GetFileName(TempletFileName);
        //             
        FileInfo mode = new FileInfo(TempletFileName);
        mode.CopyTo(ReportFileName, true);

        //  excel
        object missing = Missing.Value;
        Application app = null;
        Workbook wb = null;
        Worksheet ws = null;
        Range r = null;
        //
        app = new Microsoft.Office.Interop.Excel.Application();
        wb = app.Workbooks.Open(ReportFileName, false, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);
        app.Visible = true;

        //  WorkSheet  
        ws = (Worksheet)wb.Worksheets.get_Item(1);

        //     WorkSheet    
        ws.Cells[1, 1] = "100";
        ws.Cells[2, 1] = "100";
        ws.Cells[2, 2] = "100";
        //       
        r = (Range)ws.Cells[2, 3];
        r.Formula = "=A2*B2";

        //  Excel     
        wb.Save();
        wb.Close(null, null, null);
        app.Workbooks.Close();
        app.Application.Quit();
        app.Quit();

        System.Runtime.InteropServices.Marshal.ReleaseComObject(ws);
        System.Runtime.InteropServices.Marshal.ReleaseComObject(wb);
        System.Runtime.InteropServices.Marshal.ReleaseComObject(app);

        ws = null;
        wb = null;
        app = null;

        string path = Server.MapPath("out.xls");

        System.IO.FileInfo file = new System.IO.FileInfo(path);
        Response.Clear();
        Response.Charset = "GB2312";
        Response.ContentEncoding = System.Text.Encoding.UTF8;
        //      ， "    /   "           
        Response.AddHeader("Content-Disposition", "attachment; filename=" + Server.UrlEncode("             .xls"));
        //      ，      ，             
        Response.AddHeader("Content-Length", file.Length.ToString());

        //                   ，      
        Response.ContentType = "application/ms-excel";

        //            
        Response.WriteFile(file.FullName);
        //         

        Response.End(); 
    }

  COM  ，  ：Microsoft.Excel.x.0.Object.Library，Microsoft.Office.x.0.Object.Library 

      OFFICE,     11.0  (Office2003  )，      Com ，          Excel、Microsoft.Office.Core，VBIDE   Library.