"Windows Vista Command Line Configuration of International Settings" is on-line on MSDN

Generally its a good idea to let the users figure out their international settings, but sometimes they need to be managed in a command-line manner.  Windows Vista Command Line Configuration of International Settings at https://www.microsoft.com/globaldev/vista/vista_tools/vista_command_line_international_configuration.mspx describes how to manage the international settings from the command line