PGP Desktop and on screen keyboard

PC Tech here and I am trying to figure out if you can have the on screen keyboard on a surface pro 1 and 2 when you boot up the device. I understand that the OS has not loaded yet so the on screen keyboard wont load, but is there a work around? We have the type covers and the pros recognize it, but we are trying to get the on screen keyboard to work encase a user forgets their keyboard. Does anyone know of an encryption that will utilize the on screen keyboard.