One of the reasons I disliked my MX-5000 was the lack of a numeric keypad.

What determines when the customer is finished with the keypad?
The reason I ask this is because the customer may use the keypad in different ways, making it hard to program a functional page jump. They may enter the channel and be done; or they may continue to another channel?

You are best to just inform the customer to jump back to the main device page after they are finished with channel entries.