PeterH:
That's a curious thing to want to do. Just out of nosiness, why do you want to do that?
Well actually it's for a cocoa application to unlock a PDF, but I needed some low-level advice in a short amount of time, so I asked here 
I don't remember what I ended up doing (It's been a long weekend), but the program did what I needed and I'm done now haha
Thanks for all the help guys!