Me, I'd start by getting a remote to program. I just don't see how to simulate it without a remote!

Now that I'm done with the smartass answer -- on a T2-c, maybe you could program the up-down button under the screen to send up-down commands.

Really, though, as it says in my signature, we need to know the model numbers of the stuff you're working with. And you might want to make a set of screens that look like a sliding action is taking place if the lighting can go to preset levels... it all depends on what you haven't told us: exactly what you're using.