Well, using the 7107 and some LED displays you get a voltmeter, just look at the 7107's datasheet.
The 7107 is a fully integrated 3,5 digit voltmeter, with driver circuits for 7 segment LED displays.
The HD44780 LC-display is of no use together with the 7107.
If you want to use a dot-matrix LCD you something that can drive the thing and something that does the A/D conversion for you. Probably some sort of microcontroller + appropriate software.