Well, for one thing you are going to have to define how you plan to connect the LCD to the microcontroller. Then you are going to have to prepare two pieces of code for the LCD. One needs to be an initialize routine and the other is one that can allow you to write characters to the display. Once these are in hand and tested you can look at how to display the counter to the display. At the place where COUNT is placed out to P1 to drive the LEDs this code will be replaced with code to first get the high nibble of COUNT as a 4-bit number and then add that to the ASCII constant for "0" and output that result to the LCD display. Then extract the low nibble of COUNT as a 4-bit number and then add to that the ASCII constant for a "1" and then send that result to the LCD display.

You can find many reference codes on this site and on the web for "talking" to 16x2 LCD modules.

Michael Karas