help unpack zenonia file

[canboy]

hello
i tried to make some translation to zenonia(nds ver)
i found that all the game are pack in the gnr file
but i originally can't my self unpack this
can anyone help me
here is the gnr file

[aluigi]

http://aluigi.org/bms/zemonia.bms

There are no filenames and some small files have a format that uses compression (not related to extraction, just for information)