Excel Spreadsheet using ASP.NET

Need to create multi tab excel Spreadsheets using ASP.NET(Web) using C# you can use excel interop if necessary. These multi worksheets in a workbook needs to be created using an existing template. I have a summary template with a link to detailed page. There is also a detailed template which will be one per each data item. Any one if you can show me a demo of creating multi-sheet spreasheet created using an existing templates will be given preference.