How do i extend a class from one that i want to load from a DLL?

So far i know this. To load the DLL i use

Code:
System.loadLibrary("ShellBasics");
The class that i want to use is

Code:
ShellLib.ApplicationDesktopToolbar
I have looked around and found something about a classloader, but i wasn't to sure if this was only for use with compiled java classes or not? Any help would be great.

Thanks