Bills suggestion is one way to go definitely.
He is advising you to create a title in PPro Titler or PhotoShop or other graphics application.
Put the graphic on a video layer and select it.
Go to Effects Control Window.> Motion > Position.
Position your graphic off screen at time you want it to start. Set a key frame.
Position it on screen at the time you want it to stop. Set a key frame.
Done.