Nokia :: 3110c Change Key 1 Short Number To Access Voice Message Recorder

I have a Nokia 3110c, excellent phone still working perfectly after 2 years.Recently, I switched from SFR operator to Orange operator. SFR uses 123 to access the voice message recorder, currently accessible through a long push on key 1. Orange uses 888, so I would like a long push on key 1 to trigger 888 instead of 123. Unfortunately, how to is not explained in the manual which deals only of keys 2 to 9. I also resetted the phone to Factory Settings, and even loaded "Default Operator Settings", hoping that that would include reprogramming of key 1 to 888. No way..