Oracle8.1.7 installed in server with character set 'AMERICAN.AMERICA.UTF8' and chinese characters can be
stored and displayed properly on any sessions from server .

Oracle client 8.1.? installed in each client with character set SIMPLIFIED_CHINESE.CHINA.ZHS16GBK , and ODBC
also set to connect the server .

When User doing any query by either SQLNet or ODBC to the server , the chinese characters are not displayed properly (messive code shows)

So administator did changes in Registry for each client ,
the NLS_LANG is changed to the same value as server NLS_LANG ( AMERICAN.AMERICA.UTF8) .

while now user can see the chinese characters via sqlnet .
But when connection using ODBC , the chinese characters are still not displayed properly .

What's the cause of it and how do you think there any shortcut to solve this problem . (Basically reinstall oracle client / ODBC is quite tough job :-)
Gurus , please advise .