Cross hair laser module for zeroing

I have a bunch of crosshair lasers lying around somewhere. I was hoping to make a quick fix for lining up the mill and laser but couldn’t get it to be dead on accurate so I left it be.

Do you have a post on your laser setup? I still like to implement them lasers to see if I can ease up the proces or get rid of the need for a dimple somewhere. a push in the right direction would be much appreciated.