It should be a fairly straightforward to read the ADC and transfer the result to the LCD.
I assume that you are using the 5V supply as the ADC reference. If so, the ADC will read 0 at 0V and 1023 at 5V input. That will give about 2.048 counts per degree centigrade.
You will need to get the PIC to do some maths to get the result as deg C, which you can then send to the LCD.
However, I think that is a difficult way to measure temperature. If you need a wide temperature range, use a MAX6675 which converts thermocouple to 3-wire with one IC, no analog to deal with and no power supplies other than the 5V.
For temperature ranges up to about 150 deg C, you can use a temperature sensing IC that doesn't need a separate sensor, such as an LM95071