Have a look at Chip's page regarding Application Level Events.
http://www.cpearson.com/excel/AppEvent.aspx

Rich wrote:
Greetings,

How do I add a subroutine at the application level?

Example: When I start up Excel I want to have it bring up a messagebox that
says "test"

I can see in the VB editor how to do this at the workbook level in the
workbook open event. But I need to do this at the application level.

Thanks.
Rich