Hi,

If you change your voltage divider to a 50%-50% configuration (say 4k7 and 4k7) and then set the reference voltage for the ADC to internal 4.096V, each step of the ADC will equate 0.5mV
Multiply your ADC reading by two and then manipulate the result to read "X.XXX Volts" per Henrik's LCDOUT routine.
Yes, I understand there may be some slight inaccuracies but I have found this approach to be quite effecting in recent projects.

Cheers
Barry
VK2XBP