Im confused handling file on 32-Bit mode. Is anyone here have a FAT32 Lib function?

At the risk of sounding like some artsy retard, the answer to confusion is not abstraction. If you don't understand something, don't just stick together some functions calls written by someone else and hope they work the way you think they should. If you can't write a FAT32, try something easier.

If you're set on FAT32, I'm sure there is plenty of sample source you can dig through but I doubt there is any sort of library you can just plug-and-use.

On a little sidenote, from my experience someone with 10x the skill of someone else is usually more likely to get the job. :)

MenuetOS has a set of FAT32 routines. Take look at the source.