Thanks to both Mike H and Bob Umlas... exactly the result I was seeking.
My target audience, however, is likely to disable macros upon opening the
workbook... anyway to disable that warning?

"Mike H" wrote:

Hi,

Alt+F11 to open VB editor. Double click 'This Workbook' and paste this in on
the right

Private Sub Workbook_Open()
response = MsgBox("Hello World", vbOKOnly, "My Welcome message")
End Sub

Mike

"twiftshoeblade" wrote:

I would like to make a message appear in the form of a pop-up, like an input
or error message, whenever a workbook is opened.