Hi Aldrin,
did you study a content of basic.mc file (in help) and basic.cpp file (on your disk)? They are nearly the same, the only bigger difference is a name of main function (main in mc, MdlMain in cpp).
You have to know .mc has been used for MDL code created in "old MDL fashion" and compiled by mcomp.exe into pseudocode interpreted by MicroStation. This way is obsolete now. Cpp is the standard extension used for normal C/C++ code to be compiled by Microsoft VisualC compiler (in general by any C compiler like gcc or other, but in case of MicroStation, it has to be VisualC).
Why help file and the examples are different? In the past, all SDK examples were written as "old MDL" examples and they were converted to native code later. Help file has not been update yet to reflect this change, so it describes the older version of example. But it's not a big problem, because as you can see, the code is pretty the same.
With regards,
Jan