Hi,

Since you are new to PBP you might not be aware how a LCD works anyway. Try this link http://www.sxlist.com/techref/io/lcd.../djlcdsim.html or http://www.geocities.com/dinceraydin.../djlcdsim.html
It will give you an insight on how a LCD works.

Now you need to monitor the LCD enable and register select line too. Obviously you need a buffer inside the PIC since you serial out would be slower. While monitoring the port you can constantly loop around and then see if port!=port(buffer). This means a new data. Then dump it to the serial routine.