Apparently one cannot do this in France
One cannot do
what in France? The reval or the night qual?
The revalidation of your licence must be done by the issuing authority (in your case that being the CAA). The revalidation of your class ratings can be done by any authorised JAA examiner. Lastly, the training for the night qualification can most definitely be done in France, although you will apply for it to the CAA--that's precisely how I did mine, so feel free to ask if you need further clarification.
Have you tried calling your local BRIA, or DCS Paris? 01.58.09.45.96 for the latter.