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If you mean drilled holes for mechanical mounting etc, it is simple: You create a component with associated decal. That one has one pin, and the drill size is the hole diameter. You also should check off the "plated" box, usually those holes are non-plated.
The pad stack can (and mostly is preferred to) be of zero diameter on the outer surfaces -- or if you want the place to be visible for manual drilling on the copper, set the pad stack to be a small annular ring. That ring is OK for kitchen-sink production only -- professional PCB producers do not like such aiming-rings, and they get all required coordinates from the drill file anyway.
For "CAM Planes" on a multilayer board one should have a big enough round pad. It is for generating the required "antipad" to prevent copper to touch the hole.
The rest is easy, just place the fixing-hole components in right places on your layout, using for example the ECO function.
the best way is to make assign one more layer with drill size same and have and add pad size as per ur drill size or if u want a center point make a pad of 25 mill, name this layer as padmaster when u run the output, them using corel superimpose both the layers in the reverse manner so u can get holes in the pades as u define in that layer