A solution could be to mill a second key at a local key mechanic...
or to remove the inner doorboard do have access to the lock itself where the microswitch is located
then you can turn on ignition with your key, close the door, turn the lock from the inside and so on...
you have to use some kind of a flat screwdriver to turn the lock without a matching key in the outer door hole
sorry for my stupid english
another solution would be to turn on ignition without your key, you will find a solution