Funky Java Applet

Okay, to start off, I want to explain that what im asking probably can't even be done from what I've seen on google searches, but I thought I might post this and see if anyone knows how this would work. My experience level with Java is low, I've been studying it for a few months, did a basic applet that read a text file off of the web directory and displayed its data in the form of a roster. This applet can be found here (seeing what I did might be necessary to understand what I'm looking for) http://forums.xisto.com/no_longer_exists/

Now, what I want to do, is allow the applet to either write to a file inside the web directory (not the client's computer), or connect to a MySQL database.
From what I've seen, all of the file access tutorials for java explain how to create certificates to manipulate files on the clients computer, I want to actually change the files on the web server. If that's not possible, I'd like to try to connect to a MySQL database (which would be safer and might allow me to advance my program to the level of a login system, but that's in the future. The problems I've encounter with MySQL are purely mental blocks so far. Everything I see is about having drivers on the computer connecting to the database, and since installing drivers on every computer that runs the applet is unreasonable, and since I don't have a way to install the drivers on a web-host, I don't see how its plausible. Maybe my vision is skewered though.

Thanks - Xeta