The easiest way to handle this is to leave well alone. Why fiddle the standard system interface that users get to know and love using Office products.
I suppose you could pad the text with lots of spaces, of course you would have to change the number of spaces for each screen resolution. You would have to find out what font size the user is using. Hey you could even write a custom function make it available to all people on this forum. Might take a few weeks / months / yearrs of hard work though.
Of course you could always have a splash form which opens very breifly and then loads the main application. have a look inthe help system on how to open a form, then open another form and close the original. look for timer events (that could contorl the amount of time your splash screen is displayed)
offhand its soemthing like
Private Sub Form_Timer()
DoCmd.Close acForm, "<mysplashform>"