Bonjour,
Firstly, my condolences regarding what's happening in Paris. I'm British and my wife is half French, and i feel your country's pain.
Now, as for this project, I can do this for you very quickly, as I have recently completed an XML--> CSV convertor, and have written my own library(in C++), to read, parse, and write(to), and process, large CSV files).
There are also lots of XML libraries which enable the creation of XML schemas/documents.
What O/S is this to run on ? Windows, Linux or as a web page?
Look forward to hearing from you.
Merci