To determine a heading and path, also known as a vector, you have to have a starting point, which you may have (see below), a speed, which you have (374.16 kts), but also a direction. The direction is calculated, as you request, by applying appropriate formulae.
The math becomes involved once the plotting moves from 2-space (flat plane, not aeroplane) to 3-space and the formulae can be found online in many locations. One such location, Interactive Mathematics, provides as clearly as possible on the flat computer screen how to think about these vectors and provides the math.
If you consider that your origin point is 0, 0, 0 and the points you've provided are represented in the drawing above, you have a good portion of the information required.
I've enjoyed vector math in the past, but that was more than 30 years ago and there aren't enough brain cells to get beyond this point for me.
I suspect there's a mathematics SE better suited for your question.