I want to know how make .DLL (in subdir MODULES)

Greetings !
I'm a begginer in FS and I want to know HOW I can make add-on for FS (some .DLL in subdir MODULES) with C++.
Can anyone give to me URL where I can read about interfaces with MS FS and may-be some source examples.
Thank you very much.
Vladimir_BL
I'm a begginer in FS and I want to know HOW I can make add-on for FS (some .DLL in subdir MODULES) with C++.
Can anyone give to me URL where I can read about interfaces with MS FS and may-be some source examples.
Thank you very much.
Vladimir_BL