How to detect if player hits enemy half-way into an animation?

What I want to have happen is when an enemy winds up to attack, if the player hits him when that is happening, the enemy is stunned. How would I do that? Animation events can only be placed on one frame, so should I make a bunch of those over the frames that the enemy is attacking? Also, GetCurrentStateInfo returns when the animation starts and finishes, not just the middle.