Using the Include File Method
You can use include files to identify symbols to export. The include files must contain the declarations of the symbols you want to export. The include files can contain nested #include statements, but the DLL does not export the declarations in the nested include files. In the Target Settings dialog box, select from a list of all the include files in the project.
The include file method does not work with other compilers. However, it is similar to the .def method that the other compilers use.