Hi Christian, thanks for your reply. I'm going to use "WM_COPYDATA" since it seems to the best way to do that. I can't really alter the existing C++ app, but I'll still have a communication by messages sending between two processes because I can create a new c++ app which can use the dependencies from the existing C++ one. I'll have to make communication between my C# application and the C++ one I'll have created. I'm started looking at that. Any idea in using the elements you guys think I'll need is welcome ! Thx ! Pat.
p.f. Goudjo-Ako Bringing our energy together !