Bespoke Native Android keyboard

I need a native Android keyboard that has just 4 rows. Top row 0-9 and rows 2 to 4 for QWERTY. Also a 'Back' and 'Submit' key, nothing else, no space bar, shift etc. It's for a Motorola Xoom tablet which will be running in landscape mode on Android 4.0.4. The keyboard should be 45% of total page height. Standard Android keyboard colour except for Back and Submit keys which should be red and green respectively. Letter keys should all be in uppercase and type only in uppercase. No dictionaries etc. required.
I need this configuration of keyboard because I am going to be running a website in kiosk mode on the tablet and the only part of the website that requires a keyboard for input is where we ask the user to enter their car registration number. I want the keyboard to run natively on the tablet so I can chose to switch between it and the standard Android keyboard whenever I wish (by going into settings).