Go to ebay and do two searches, one for a "stepping ring" or "step up ring" and another for metal hood. I needed a metal hood for my 50mm f1.8 Canon which from memory is 40mm (not sure about the 35mm f2 Canon lenses which I think is what you are speaking about but I suspect its the same). Bear in mind that many vendors on ebay sell 40mm hood so if you find one you will not need the step up ring. If you need for example a step up ring for a 43mm hood on a 40mm filter ring then the step ring search would be something like "Step ring 40mm-43mm" Substitute the actual diameters you require. The search for hoods is best undertaken when in the ebay lens section and I think the stepping rings have their own sub category under camera accessories.
Also you can try an ebay store.....Heavystar is a well known store (which has a presence on ebay) that sells such things but there are others. Below you find links to a ring and hoods I like and have purchased for various lenses I use. The hood I prefer which works with a 43mm filter mount works on Voigtlander 40mm f1.4 lens (which itself has a 43mm filter) so should work on a 35mm f2 even though it looks too deep. Because its 43mm it is big enough to fit of several different lenses with changes to the step up ring to match them as needed. And its wide enough to cope with a lens that is wider than 50mm. Hence I use the same hood on a Leica 50mm f2 (39mm filter), a Leica 50mm f1.5 (41mm) and an Olympus lens for M4/3 with a 37mm filter ring - all using different step up rings and the single hood).
I have also included a link to a more traditional type hood with vents / cut outs.
My favourite hood for rangefinder lenses
Traditional Leica type vented hood