Hi Nuclear Paul, :welcome to Armaholic.com
I havent been diggin into this yet however I did check the wiki page about the addaction command
And I noticed one thing there
unit addAction [title, filename, arguments, priority, showWindow, hideOnUse, shortcut]
And the following:
showWindow: Boolean - Display associated window
You might to set that to false and see if that removes the onscreen message.
But again, I havent tried this myself yet and I am at work so I cant test it neither for you now.