The biggest issues are that you would have a helluva time choosing what you wanted to scroll and it would probably look like a child window, with a title bar and controls, and it wouldn't scroll across the screen unless your window was already in full-screen mode. Also, you would be cranking your machine hard to do it from Access.
You COULD do it with an unbound text box on a form that has a timer. Every few milliseconds (yes, milliseconds!) you could pass a timer event to some class-module-based code underlying that form.
Now, why do you NOT want to do this?
1. Specifying what to scroll would be painful since the form has to be unbound. You would have to do a lot of programming.
2. If it ain't Access data you want to scroll, it is even MORE painful 'cause of the work you would have to do to get onto the form.
3. Controlling it (starting, stopping, changing colors, other attributes) wouldn't be easy either.
4. Since the VBA code is not fully compiled (it goes to some level of p-code rather than true binary), it is very inefficient. Fast timer ticks plus inefficient code = loaded-down CPU. And a SLOW timer tick rate would look uglier than a 70-car pile-up on the Autobahn.