This example identifies the Office Assistant balloon by setting the Private property to 129.
Set printerOrientation = Assistant.NewBalloon
With printerOrientation .Heading = " Print portrait or landscape?"
.Text = "Click OK when you've selected the " & _
"printer orientation."
.Labels(1).Text = "Portrait"
.Labels(2).Text = "Landscape"
.BalloonType = msoBalloonTypeButtons
.Mode = msoModeModeless
.Button = msoButtonSetOK
.Private = 129
.Callback = "PortraitOrLandscape "
.Show
End With