Beckhoff TwinCAT & COM interface

Hi, I'm trying to access the Beckhoff TwinCAT PLC via its COM interface. The documentation is not too reach, nor are there any code samples. Anyone have experience? - What I want to do is, read and write variables whose names I know, and receive events when some data changes. I can do this from a C# program, using ADS.NET, but for reasons beyond my control, I have to use C++ and COM . Thanks for any help.