Blitz Terrain/Align Mesh

I was wondering, how can I adjust a mesh's rotations to align on a BLITZ terrain WITHOUT using the collision system or a camerapic.
the informations I would like to give are the X,Z (and Y?) positions on a terrain then, it will give me the normals of this position.

Is that possible ?

You'd need 2 x vectors to compute the vertex normal so that won't work. If it's just to place objects initially , set the terrain to entitypickmode 2 , and do a linepick straight down, then aligntovector entity , pickednx, pickedny, pickednz , 2 and position it using pickedx, pickedy and pickedz.

Can't it be calculated from the TerrainHeights of the surrounding 4 vertices?

Yes, but you would still need to get 2 known vectors from that info.