Recently a user asked this question in MSDN forums. He had MBCS enabled for his application and also wanted to enable unicode characters in a particular edit control. Note MFC only create unicode controls if UNICODE is defined in project settings.
So in order to explicitly create controls that support UNICODE characters we use the ‘W’ functions. For example: for our user he should use “CreateWindowW” function. Note the last ‘W’ in the function. ANSI windows are created by calling “CreateWindowA” function (this also means that we can explicitly create a non-unicode control).
Also make sure you use only UNICODE API’s for a control created in this manner. For e.g. always call GetWindowTextW instead of GetWindowTextA. Never use MFC on such a control if it’s not created by MFC framework, I mean don’t call CWnd::Attach on this control. Mainly because MFC is operating in non-unicode environment but our control is a UNICODE one.
Now once such a control is created you can paste characters of different languages, for e.g. Chinese, Japanese, etc even though the application is not a UNICODE supporting one.