Not sure if that's possible with the MW version of the CS or not. It's pretty much the only thing keeping me from finishing my mod.
Right now, the only thing I can cause the script to trigger with is a GetSpellEffect on the player, (by adding a self effect to the spell). That sort of puts the mod on the "honor system", trusting the player not to just cheat and cast this spell whenever they want, not at a living target.
Any help on this would be fantastic. It's literally the only thing I can't figure out, and haven't been able to figure out. Every other part of my mod I've gotten pasted down perfectly.