>Since you are dealing with the lens as if it were a 36mm you >could get the 35 mm hood and use it. It is HN-3
Sorry - the concept of "cropping" with another hood usually has a major issue - often making an f2.8 lens close to an f4 lens.
The example I most use is the 70-200 VR which has a 77mm filter thread. Dividing 200mm by f2.8 confirms the minimum front element size for f2.8 brightness is 72mm. If you divide 72mm by 0.66 (for the DX crop)you can use a hood which crops down to the equivalent of 48mm filter thread without optical vignetting on DX. Trouble is dividing 200mm by f4 confirms if you restrict the light gathering area of the front element to 50mm you have f4 light gathering at 200mm, not the f2.8 Nikon build into the lens. You would probably be OK at the short end where the front element is "oversize". Dividing 70mm by f2.8 confirms the minimum element size needed is 25mm, so a "cropping hood" might help at the short end of a zoom.
Photography is a bit like archery. A technically better camera, lens or arrow may not hit the target as often as it could if the photographer or archer does not practice enough.