Does it exist an API for “International Settings” in Visual Studio?

Question

I'm working on Visual Studio Extensibility and I need to set the "shell" language from code. In other words, I'm looking for an API to do the same you can do "by hand" with the Tools -> Options... -> Environment -> International Settings property page.
Up to now I didn't find any reference: hints and suggestions are welcome. ;-)
Thanks in advance.

EDIT: to clarify a bit the question, I need to set the current language of Visual Studio itself (actually of an Isolated Visual Studio Shell).

Answer 1

I post here the current results of our (my coworker and me) search.
We found something at http://msdn.microsoft.com/en-us/library/ms165643.aspx .
In particular you can access that kind of options with
DTE.Properties("Environment", "International")

Answer 2

Is this what you're looking for?

http://support.microsoft.com/kb/914356

Answer 3

Yes, ask on win32 api newsgroup (it's a FAQ)

news://comp.os.ms-windows.programmer.win32