An undocumented message ID which switches a console window to full screen.

#include <windows.h>
#include <conio.h>
void main()
{
 char console[120];
 strcpy(console, "name of the app");
 GetConsoleTitle(console, sizeof(console));
 HWND myconwnd = FindWindow("tty", console);
 SendMessage(myconwnd, WM_COMMAND, 57359, 0);
}