How do I generate a Protective barrier for Cere?

I've been trying to find an answer to this question for THREE MONTHS.  One more time: I need to know what key bindings I need to set for my keyboard mouse setup so that I will be able to generate a protective barrier for Cere in Stop the Assault.  Just telling me which key you bound to do this is no help at all.  Neither is telling me to switch to the default set up—that doesn't work. Until I know what key bindings I need to set up, I cannot advance beyond this point in the game.

I need to know what what action the keys need to be bound to!  There is no action for generate Cere's protective barrier listed anywhere in the game controls as an option!  Telling me which key you bound to, without telling which action it needs to be bound to is absolutely no help whatsoever!  Especially since this action appears to require the use of multiple keys.

Surely to God, someone out there must know which damned keys on my keyboard need to bound and what action they need to be bound to.  For three months I've been trying to get someone to answer this extremely simple question.  Can you imagine how frustrated and pissed off I am right now?

Attempting to get an answer to this—or any other question—from EA is an exercise in futility. So, I am hoping that at least one of my fellow gamers will be willing to share this apparently top secret information with me, that EA is guarding more jealously than Imperial Death Troopers guarded the Death Star plans.