Flip the blade out and use it 'old style' in the keylock. Be ready to put the key in the cubby on top of the dash and power the car up as the alarm will go off. If the interior lights do not come on when you open the door then the 12v is flat too.
I actually recall doing exactly that, but as I am not presently with the car (I am providing telephone support) the actual problem is that I cannot see the keyhole. I also cannot find any diagram or photo of the keyhole online.
Can you please describe precisely where the keyhole is on the driver door?
Once opened, would charging the main battery divert any power to the 12V battery?