Full screen when opening external exe.

Hi There, I’m trying to open an external application while in Unity3D Full Screen Mode. I need this so the Player can access information then carry on in the game after closing it. The problem I have encountered when using the below code is that the external program opens alright but the Unity3D program becomes minimised to the taskbar.
My question is… How can I have a Unity3D program stay in Full screen mode when I open an external application…? BTW… it works fine when in a Window Mode.

function Start () {
    Application.OpenURL ("externalapp.exe");
}

It’s not possible to run an application on top of a fullscreen application. This is a limit of the way operating systems work: fullscreen applications take over all screen rendering. Fullscreen applications are modal (meaning you can only run one at a time), and they cannot appear behind another app.

So the only way to get what you’re asking would be to set the Unity app to windowed before you open the other app, or to let the OS minimize it while the other app is running and restore it when the other app closes.