How to: Programmatically Add New Worksheets to Workbooks
You can programmatically create a worksheet and then add the worksheet to the collection of worksheets in the workbook.
Applies to: The information in this topic applies to document-level projects and application-level projects for Excel 2013 and Excel 2010. For more information, see Features Available by Office Application and Project Type.
To add a new worksheet to a workbook in a document-level customization
To add a new worksheet to a workbook in an application-level add-in
The new worksheet is a native Microsoft.Office.Interop.Excel.Worksheet object and not a host item. You can also generate a Microsoft.Office.Tools.Excel.Worksheet host item from the native Microsoft.Office.Interop.Excel.Worksheet object. For more information, see Extending Word Documents and Excel Workbooks in Application-Level Add-ins at Run Time.