I think this would require a root signed app in order to work. Without this, the best we can do is to disable the PIN requirement on the CS4070 using the following setting in config.ini:
Once this is done, the Android pairing process is simplified as follows:
1. Press pairing button on CS4070 until beep is heard - blue LED will flash quickly
2. Enable Bluetooth and run BT discovery on Android device
3. Look for keyboard device with ID starting CS4070:
4. Select device to pair - pairing should complete without any further input.