Clip a PCB against a 3 mm plastic protection
Google search: Double-sided tape PCB pillars


You can get these in various sizes to suit different heights and different holes: -



They have double sided tape on the bottom so they just fix in place and you should be good to go. Here's a different type: -



And a range of heights: -



You can even get them that work with a screw too: -



There are plenty of options and quite a few suppliers: -