How to force user to save excel file in excel?

I create a .xls file programmatically and open it in excel

eg:

Process.Start("c:/blabla.xls");

I delete the file when excel is closed, so I would like to ask the user if he wants to save the file when it is closed, and ideally make him save it in a new place.

I hope there is an argument that I can make to succeed during Process.Start