finally I solved my problem to assign style to HTML parts,
so thanks a lot for your suggestions!
Now i have another problem, but needs another topic:
sometimes, after the creation of some docx using the docx4j libraries, in my logs compare an error like this:
java.lang.OutOfMemoryError: PermGen space
...and the entire application crash.
i cannot understand why, untill the fourth or the fifth docx it's all ok, but at one point the application goes wrong with the message i've just written.
Thanks in advance for help,