if you want to display a message while macro is running in a workbook to the user. Check the snapshot below -
and you want to display the message like below
Here is the code:-
Sub displaymss()
Application.ScreenUpdating = False
Application.DisplayStatusBar = True
Application.StatusBar = "Please wait while performing task"
'-------------add your code here-----------------------
Application.StatusBar = False
Application.ScreenUpdating = True
End Sub