How to use matrix nodes for an aim constraint setup

[Daniel_van_Westen]

Dear Forum,

I hope there is someone here who knows a bit more about matrix nodes in Maya than I do.

My problem is the following. I have 2 (locator1, locator2) locators which cause 2 other locators (pointOnSphere, pointOnSphere1) to slide on the surface of a Nurbs object (via closestPointOnSurface node). To read the tangent of the surface, I use a pointOnSurfaceInfo node.

Everything works wonderfully. However, I have absolutely no idea how to integrate the aimMatrix node into my setup so that pointOnSphere1 points in the direction of pointOnSphere (I only want the y-rotation to change).

I hope it is somehow understandable what I am trying to achieve…

Here is an example file: https://www.dropbox.com/scl/fi/psmhh9wsp8tf0pm7xn7i2/slideExample.ma?rlkey=ble7zjqfa2oz16uc6cb3dn5dx&dl=0

Thanks for your time!
Daniel