hi
I’m try to convert a .root file to a ntuple PAW file.
is it possible?
It might or might not 
ROOT supports may features that can not be implemented easily in hbook. Hence a fully automatic translator is not possible to write.
So you will need to write the translator your self (writing fortran code that will create you hbook file and call a C/C++ routine that would fetch the data from the root file and translate it into a form understandable by your fortran code)
Cheers,
Philippe.
PS. Out of curiosity, why do not need to produce hbook files?