Alright! Now, let's see if I can describe this...
I have two objects in an isometric display. One object is taller than the other, and the shorter object is trying to shoot something at the top of the taller object (Headshot!). I'll just call it a bullet.
Also, the tall object and short object also have invisible objects associated with them, to represent their actual placement on the field and the size of them in an invisible, overhead layer, to make collisions easier, and handle X and Y axises better, etc.
Now, the bullet that will be shot from the small object to the tall object will travel at a direct line. This bullet is invisible. The invisible bullet has an object that represents its placement on the isometric display, and an array/ Alterable Value is used to determine the elevation of the bullet above the ground. Works fine.
Now, here's where the math comes in. What I'm trying to do is figure out a formula for how much the bullet has to rise (add X to Alterable Value) so that it'll appear to hit the head of the tall object once the invisible bullet hits the invisible representative of the tall object.
I tried using the slope formula (y2-y1)/(x2-x1) and multiplied the resultant value by the speed that the bullet was traveling (Alterable Value * (Speed( "Bullet")*8)), and it worked fine except for when there was no difference in the x values, which would give me an undefined slope, as apparently that method only works for objects in 2D space only... Something I should've known.
I think the solution has to deal with the distance formula and determining that distance to then be multiplied by the speed of the bullet and some kind of 3D slope to make it work. ... But I'm just guessin'.