When you create a mission script using VC++, it essentially creates a 'blank' mission for you to fill in. Of course, you may not want much of what it autogenerates for you and have to change things anyway.
FMSE is a GUI that creates mission scripts, but it is very limited.
Remember that because the game was written in C++, and that the mission scripts are also written in C++, anything you can do in a C++ program, you can also do in a mission script. It is this flexibility that makes using actual code essential.