That's better, although your links are now "orphaned" in you other thread:
http://www.8052.com/forum/read.phtml?id=102796


There is nothing magic nor mysterious about a "driver" - it's just another piece of software!
Therefore, you write a driver exactly the same way you'd write any other piece of software:

Define precisely what it needs to do;

Design a structure which achieves that requirement;

Implement your design in your chosen language for your target system.

So, your first step is to Define precisely what you want this "driver" to do. I guess you'll want at least:

Clear the entire display;

Write a character to a given position in the display (this will include the character encoding already discussed);

Write a character to the "next" position in the display (here, you need to define how you will handle messages longer than the display - will you scroll, or what?)

Once you have a clear definition of What exactly you need it to do, How to do it should follow quite easily...