I dont get it, whats the problem?

Note that your going to have to include windows.h to do that; buy the way why not learn windows and make your game windows based because I hate to tell you man but dos is dead.

hay if ur using the win32 API then use vertical keys like VK_UP so ur code will look like this:

LRESULT CALLBACK MessageHandler(HWND hwnd, UINT message, WPARAM wparam,
...

the code goes like this:

try
{
Runtime rt = Rintime.getRuntime() ;
Process p = rt.exec("Program.exe") ;
InputStream in = p.getInputStream() ;
OutputStream out = p.getOutputStream ();
...