Distance-Dependent Parabola

I was wondering if someone could help me out by providing a formula for a distance-dependent parabolic curve. I am moving a unit along a z (flying height) arc to make it look as a catapult missile. I decided while testing that it looks silly when the projectile's peak height is the same no matter if the target is close or far away, so I need to add a modifier that will lower the peak for a close target, and raise it for a far away target. In other words, realistically.
Thanks.

Check my JumpParabola function, the max height of the missile/unit depends on the distance and the curve argument.

Cool, thank you.