The easiest option would probably be to just get a separate number pad. There are a lot of them floating around; even Deck still has a few of their 21-key boards available
over here. Alternatively, if you don't use some of the keys on your keyboard right now, you could change them to number pad keys, using a registry edit that seems to keep getting mentioned on these forums. But that will probably only work if you just need one or two keys.