All you want to do is a simple Analog to Digital Converter, these come in a single chip with a built in LCD display driver. Like the ICL7106 or similar (see the link below gives all the information and details)
http://www.intersil.com/products/deviceinfo.asp?pn=ICL7106
They are really cheap, all you need is that chip a LCD display, a few resistors, caps and 2 pots etc to set up the circuit, build it all on a small section of prototype PCB.
No programming required.
Edit:
Just searched Farnell electronics
ICL7106 Chip: $5:11