Globalization :: Forms / Reports Chinese Character Support?

We have an existing db (10.2.0.4.0) and forms (11.1.2.1.0) application, that we're trying to extend to support Chinese characters. We're looking to add some unicode (nvarchar2) columns to existing tables, rather than converting the whole db charset. I've pasted my environment settings below. What I've found so far in trying to create a local (ie. running the form in Builder with local weblogic running) test form, is that I can insert the chars ok (using plsql developer) and the test form can display them correctly, but cannot write them back to the database. They appear as upside down question marks in any records the form has created. 

Env variables:NLS_LANG = .UTF8 Database:NLS_CHARACTERSET = WE8MSWIN1252NLS_NCHAR_CHARACTERSET = AL16UTF16 1)

So, how to get the form to write the characters back into the database correctly? 2) The chinese chars will only be relevant to a few forms inside the app, are there any settings local to the form that will enable unicode support, rather than setting at OS level. ie, an alter session, or equivalent? 3) Oracle Reprts doesn't appear to have an nchar datatype unlike Forms, is there anyway to get Reports (generating PDFs), to include Chinese?

I now have the chars writing back to the db ok. If you do it via an INSERT statement from inside the form, it doesn't work. It appears the value is sent to the db in the normal charset rather than the national charset, and it's written as a question mark. If you pass the value from the form into a back end stored proc though (which does the insert) it works okay.