Your right, you cannot access those from Kix. Those are low-level COM interfaces (the standard is that COM Interfaces start with the letter "I") ... the good news is that microsoft (usually) provides scriptable interfaces to these same low-level interfaces - they are called dual-interfaces.

Bottom line: While the low-level interface reference material can be usefull, it is really not meant for scripting. What you need to find is an ADSI scripters reference guide.