Help Authoring Tool for Vista Operating Environment

[carolynmedlock1 at juno.com]

I'm a Senior Technical Author who just assumed responsibilities for developing online help for Vista operating environments, including translation of the help in 16 languages (will go up to 25 based on Dell and HP requirements). 
We are having a hard time finding a help tool that handles translated help for double-byte characters (Japanese, Korean, Russian, Chinese Simplified, Chinese Traditional). I am located in the U.S. but work for a company in the UK. In the UK they are using a tool called TCToolbox. We are not sure it will handle all the translated information. Here in the U.S. I started using RoboHelp but it would not handle the double-byte character languages.
I have been told that Madcap may be an option? Has anyone else had this challenge? Have any recommendations? Vista requires a .chm help file output.
Thanks for your help.
Carolyn Medlock
Cambridge Silicon Radio, Inc.