running a gui program in the background - c++

Question

i created a windows service that will run another program. but now i want to run a program that has a gui but in the background so i don't want the gui to be visible. this is the code i used for the service
But i can't edit the gui program
is there a way to set the gui to hidden or set visible = false from the service program?
the service is a windows service created in c++ using visual studios
i used CreateProcess to start the exe file
here's the code i'm using to run the program from the service:
path = "C:\MyDirectory\MyFile.exe";
STARTUPINFO info={sizeof(info)};
PROCESS_INFORMATION processInfo;
if (CreateProcess(path, cmd, NULL, NULL, TRUE, 0, NULL, NULL, &info, &processInfo))
{
::WaitForSingleObject(processInfo.hProcess, INFINITE);
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
is it possible to hide a gui without editing the program itself?

Answer 1

The closest you are likely to get will be setting the wShowWindow member of the STARTUPINFO structure. Even then it will only work if the application honors the nCmdShow parameter in WinMain.
STARTUPINFO info = {0};
info.dwFlags = STARTF_USESHOWWINDOW;
info.wShowWindow = SW_HIDE;
if (CreateProcess(path, cmd, NULL, NULL, TRUE, 0, NULL, NULL, &info, &processInfo))
{
//...
}