Very Technical Question/Problem

Question

Is it possible to create classes/methods 'on the fly'?? I have business rules that change. I want to create a way for users to create new methods (and new classes) or replace the 'code' in existing methods. All of these business rules would exist on the server. Ergo the classes would exist on the web server. Can the compiler be invoked from a method on the server? Or for that matter create a listener on the server to take these new classes/changed classes and compile them and get them in the classpath (or the C# equivalent of a classpath). Anybody know? Or am I chasing a car I'll never catch? Thanks John