3D MODEL SHAPE ADDITIONS

Hello, we have a 3D model that we want to add small rectangle shapes to. This is for a replacement server grill and these small rectangles are for the screws that go through the front of the server chassis into this server grill. There are three images attached. The green one is of the 3D model right now, with black rectangles showing where want those to go. The second image is of the current server grill, with the screws in it. The third is from AutoCad Fusion 360. We want to use that program to move these rectangles around in on our own, so we can make adjustments ourselves, to where these rectangles align with the screw holes.