hi,
you can do this with a custom animaction curve, going from 0 to 1 in the horyzontal axis. and 0 to 1 on the vertical axis.
this way you have a template for your trajectory, that you then multiply by the distance and the height you want, and use that as your path for the projectile.
not an easy task, but very much doable.
else, you can go all out with a proper equation based computation, that's also doable in PlayMaker, but you need to have the equation to begin with.
Bye,
Jean