How to make a projectile curve on X & Y axis?

[bruunk]

I want to create a spell that will work like firebolt, but it will also shoot 2 lesser firebolts that will arc towards the target, so 3 projectiles total:

Target -->.......O
Projectiles ->.( | )
Caster -->.......X


These fireballs dont need to do damage themselves it just needs to look that way.
How would I accomplish this?

and again just to be clear I do not mean "projectile - missile arc" in the object editor.