title: C# Excel Add In -- Programatically Add In Memory Drop Down/Pick List
body: <p>I have been experimenting with creating an Excel add in in C#.  I was wondering if it is possible to programatically create a drop down list for a column where the items do not have to be in the worksheet?  That is, I know it can be done using a data validation and a range of cells but I do not want the list of drop down items to be visible to the user/to be editable.</p>
  
  <p>Any insight/links to aid in this would be greatly appreciated.</p>
  
  <p>Thank you</p>