Do you bind a key to give the N52 temporary control over the priest, and you mouse over to the priest's screen with Synergy?

I was thinking of making the N52's space bar my shift state key, which would also serve as the trigger or hotkey to tell Synergy that I want to broadcast those keystrokes to my priest while the hotkey is pushed down. And when I release the hotkey, stop broadcasting. Or is that even possible? Otherwise, how else would you let Synergy know when to broadcast and when not to? Or do you have to mouse over to the priest's screen, then start punching keys?

Thanks