Targeting Spell to Non-Targeting spell

I'm making a shockwave that casts towards the facing angle of the caster.
How can I make the shockwave spell not able to target?

You can't. However, what you can do is give the hero some other no-targeting spell and when he casts that, use triggers and a dummy caster to cast a shockwave spell in the direction the hero is facing.

I made a dummy unit that controlls the main hero and casts spells..