Sorry for my bad english...
Found a solution

I made a little script: when the player press one of his commandMenu key(space), an image is shown to hide the center of the screen, when he press the "menuBack" key (backspace), the image disappear.
Key list of "forceCommandingMode" and "menuBack" are updated every 2 seconds.
That's not perfect, but it works...
Here a demo mission:
http://team-bac.net/bac/JOUEURS%20BA...t.Chernarus.7z