It's not that hard to read what he wants... He wants a register system that shows how many in total have registered in the server, so when people register, or connect, it'll say "XXX unique accounts created".
OP: You need to look around, there's many tutorials on how to make a register system, and with a little bit of reading of the Pawn handbook, and the various tutorials on the forum, you'll find what you need to do.
https://sampwiki.blast.hk/wiki/Category:..._Documentation
https://sampwiki.blast.hk/wiki/Scripting_Basics
https://sampwiki.blast.hk/wiki/Category:Tutorials
Even though some of it will be out of date, it still holds reason and merit to be looking at it. Even if you just read it and note how code is laid out, and how functions and callbacks work.
The real reason I say this, is you've already posted 3 threads, in your eagerness to start scripting. There no doubt will be more if you don't get sent to these pages and shown where to start.
Have fun, and be sure to keep your code neat, and indented correctly... You'll see why when you hit over 100 lines or so.
(I posted this when there was only one reply on the thread, and really, it's not that hard to read what this guy really wants...)