Exporting a visual studio c++ project for use in another project, without revealing the .cpp and .h source files

I have a visual studio project called

"TopSecretProject"

that I want to share with an anonymous developer user, without revealing any of my code, including the header files (Since my .h files include the structure of my project ant the user cannot know about it).

The user should receive:

1. A list of function names that he may call (depending on the permissions that the user has) and the user should be able to develop a program using these functions as black boxes.
2. My sealed TopSecretProject, that he cannot open.

Is this scenario possible in any way?

I tried the following solution but failed:

1. Exporting TopSecretProject as a static library.
2. Creating a new VS project for the user, and adding the .lib to the user project.
3. Copying all the .h files to the user's project and creating a pre compiled header file.
4. removing the headers (now that I have the .pch I don't need them anymore)

The pre compiled header is rebuilt in any run and thus removing my first pre built pch... I also tried to copy the pch directly from the TopSecretProject but it didn't help.

Thanks very much in advance!!