how to attach excel sheet in vb.net

Excel Connectivity in VB.NET[^] may help you get started.

Assuming that you will be creating an Add-in for your application.
Import the following:

Imports xl = Microsoft.Office.Interop.Excel

Dim xlApp as xl.Application;
xlApp = Globals.ThisAddin.Application                 'Get the application object 
Dim workbook As xl.WorkBook = xlApp.ActiveWorkbook    'Get the active workbook object
Dim worksheet As xl.WorkSheet = workbook.ActiveSheet  'Get the active worksheet object

Now you can use the properties of your worksheet in the way you want.

However if you want to open a simple workbook, then you can simply do this :

Process.Start("excel")