Extending IMAXScriptFunction in C#, I've implemented the interface and have been promptly presented with a ton of methods and properties.  :)

        public IValue Body { get; set; }

        public GlobalDelegates.Delegate21 CCallableFn { get; set; }

        public short Flags_ { get; set; }

        public short KeyparmCount { get; set; }

        etc.

I could sit here and figure out all this stuff, but why do that when I can just modify a sample project?

P.S. I'm well versed in MaxScript, and experienced in writing C# projects and Max SDK C++ plug-ins, so a basic C# sample project is all I really need.