Locking/Not transforming axis when using FABRIK

Hey guys, my first post here. Got a bit frustrated after not finding the answer on the web.

I’m trying to translate a bone towards an object in space but only in X and Z axis. If I break the location vector and set Y to 0 the IK will try to move it towards world’s Zero point on Y axis when I just want to leave it… blank, not translate in Y at all. I’m guessing the trick is is to feed FABRIK with some relative vector data and set the function itself a certain way but I have no idea how.

Any help really appreciated