Unity Android and XPeria Play

How do you access the custom device buttons on the Xperia Play via Unity Android?

Input.GetKey (KeyCode.LeftShift) = Left shoulder
Input.GetKey (KeyCode.RightShift) = Right shoulder

Input.GetKey (KeyCode.UpArrow) = Up
Input.GetKey (KeyCode.LeftArrow) = Left
Input.GetKey (KeyCode.RightArrow) = Right
Input.GetKey (KeyCode.DownArrow) = Down

Input.GetKey ("joystick button 2") = /\
Input.GetKey ("joystick button 1") = []
Input.GetKey ("joystick button 3") = O
Input.GetKey ("joystick button 0") = X

Input.GetKey (KeyCode.Pause) = SELECT
Input.GetKey (KeyCode.Return) = START

AndroidInput = TouchPad