Total Newbie...

[skimask]

It is hard soldered....

Well, then I guess I'd check around the microchip forums a bit and see if you can find any 'libraries' to handle the LCD for you on that board, that is if you don't want to write the code yourself.
Using the LCD as it sits on that board can be done...it's not impossible by any stretch. It's just that you'll have to do all the leg work.

The Pic is connected to the expander like this:
PIC Expander
RC3 --> SCK
RC5 --> SI
RF6 --> Reset

Knowing that How do I cammand the expander to do what I want it to do?

First thing you've got to do is get your hands on the datasheets for the I/O expander and the LCD itself, which as I said before is most likely a Hitachi 44780 parallel input compatible LCD, almost any datasheet for an LCD with 14 or 16 pins on the inputs will most likely work just fine. Because without knowing how to run the I/O expander or the LCD, you'll be stuck.
But for now, maybe hang some LEDs off the I/O outputs of the expander. Once you can command that thing to do whatever you want, the LCD will be close behind...