If this really urgent for you, you could try to explain your problem much better.
My output of my C++ program is a text file called Centre_Cartouche.txt
My output is two text files called brd.txt and sym.txt
What does it have to do with your problem?
My debugger tell me that the simulation works.
What is simulation, and what does it have to do with your problem?
But my file Centre_Cartouche.txt is not create.
Did you make sure the code that creates this file really executes? Did you debug your code?
EXE and DLL have the only one most significant difference: Windows loader automatically calls main() when loading EXE, while with DLL it calls DllMain(). Besides, DllMain() is not intended for code execution in the sense how it goes with EXE's main(). DLL is a bunch of functions that have to be called explicitly by other modules, EXE or DLL.