Unfortunately, virtually all Paris parish records were destroyed by fire in 1871. Some attempts have been made to piece some of them together again using other sources. If you can find the name of the person you want here
http://archives.paris.fr/s/5/etat-civil-reconstitue/?there may be some hope, but this is just a sort of list, more or less the equivalent of the "tables décennales" and the details are only available in the Paris record office reading room.
There are a few parish registers that escaped the flames and some copies that were made before the fire, but you would need to know the parish, I think, though I don't have any personal experience of searching in the Paris area. As far as I can see they are held in a variety of repositories.
I know some family history societies are working on legal documents in the National Archives to extract genealogical information but I don't know what years are covered. You could look here as I think at least some of the results have been put on this site:
http://www.geneabank.org/englind.htmlYou won't be able to see any details, as you need points to do this, but I could look for you if you find anything of interest. And of course, there is always Généanet which has been suggested to you before, I think.
If no one else has more information and/or more helpful suggestions to make, I could make some enquiries at a big family history fair in Paris on 10th and 11th March if you don't mind giving me any details you have about the person you are looking for.