Align Orient a position on a reference orientation and lock the Z axis

Hello,

I try to realize the align orientation to position in Rapid language. (Function that exists through the robotstudio interface) oriented towards the reference position

I want to align the orientation by blocking the Z axis

The z axis of my tool is not aligned with tool0. The tool is a milling cutter. I want the wrist always to stay in the same direction. The tool is rond.

if I change the angle Z this influences the angles X and Y. Because the convention Roll Pitch Raw 

My idea is :

1 - make off-line tangent trajectories

2 - In langage Rapid compensating the diameter tool

3 - Align Orient on a reference orientation

4 - Execute the trajectory

The change the diameter tool is easy. Not modifie trajectory off-line