thank you my forum it 2.3.4 the new version, it a possible to covert?
You would probably be better off to look for a converter to phpBB 2.0.23 here:
http://www.phpbb.com/
Then create a "dummy" conversion to phpBB 2.0.23 to ascertain what your problems may be. Maybe you won't be able to simply switch from one to the other and retain all the Db functions, as is usually the case.