Need assistance with "projectile" setup

So I have an iron golem that I would like to throw an entity at the player (in this case a book) and do damage.

I first tried the "shoot" skill, but quickly realized it was limited to eggs, potions, pearls etc...

So then I thought maybe I could use the projectile skill, but I'm not sure if it only supports particle effects.. or can I use item as well?

And if I could, how would that syntax look? thanks!