>but if use below code, i must offer path file , then i must save the file first........
>
>How to export the excel and not call book1, if user want to save , then save the file and default the file name call aa......
>Not save the file in direct paht first....
>
>How to change my default Workbook template?
>
>

>XL.ActiveWorkbook.SaveAs(path and name of the file, Format Of The File)
>

Offer the file name BEFORE you start the Excel.
The example is for C# (I just learn it right now :-))

using Excel = Microsoft.Office.Interop.Excel; 


SaveFileDialog dlg = new SaveFileDialog();
dlg.FileName = "YourName";
dlg.Filter = "Excel Workbooks (*.xls)|*.xls";
if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
   {
     Excel.Application xlAppl = new Excel.Application();
     Excel.Workbook xlWB;
     Excel.Worksheet xlSheet;
     xlAppl.Visible = true;
     xlWB = xlAppl.Workbooks.Add();
     xlWB.SaveAs(dlg.FileName);
     ....
     // Your code here
   }