CB_SETLOCALE
An application sends an CB_SETLOCALE message to set the current locale of the combo box. The locale of a combo box is used to determine the correct sorting order of displayed text for combo boxes with the CBS_SORT style and text that is added using CB_ADDSTRING.
wParam
Contains the locale ID the combo box will use for sorting when adding text.
lParam
This parameter is not used.
The return value is the previous locale ID. CB_ERR is returned if wParam specifies a locale not installed on the system. In this case the current combo box locale is not changed.
A locale ID can be constructed using the MAKELCID macro. The language ID is made up of a sublanguage ID and a primary language ID. The MAKELANGID macro can be used to construct the language ID.
CB_GETLOCALE