Sorry, I'm going to stop this before it gets to the point where it needs to be censored. Nitric acid is the principal acid used in making explosives and as such it's probably not a good idea for anyone to get into the details of making it on our newsgroup. However, to answer your question, nitrocellulose has a very different structure than nitrate salts; the nitrate group is bound by a covalent rather than ionic bond, so you can't use the same methods to make nitric acid. There are some ways of chemically liberating the nitro group for use in other reactions, but they use a lot of exotic laboratory chemicals.