How do I fire a laser at the player's Y level.

I have my Enemy AI script basically all setup. It shoots the correct direction based on the Enemy's rotation but if the player is on a higher or Lower Y level, the enemy still shoots straight based on its own Y level. I'm using a simple instantiate method with everything working but the rotation of my laser can't fire upward or downward. How can I make the enemy aim up or down without altering the actual rotation of the enemy?