Hello Scott,
Many thanks to your comment and hint to:
#define SB_SETTEXTW (WM_USER+11)
that points me in the right direction, it seem that i had to inform the Statusbar (msctls_statusbar32) to switch to use Unicode (SB_SETUNICODEFORMAT / CCM_GETUNICODEFORMAT Messages).
So SendMessageStringW(Handle(This), SB_SETTEXTW , lptr_part - 1, as_text) did not work for the 32/64Bit Code. Seems to be clear now if msctls_statusbar32 is default created with ANSI charset settings.
I still using SendMessageA(LongPtr hWnd, ulong Msg, LongPtr wParam, Ref string szText ) Library "user32.dll" alias for "SendMessageA;Ansi" to set the Statusbartext
This seems to work for 32/64Bit Code.
I’m not a C++ / MFC / WIN32 API Programmer, but I am aware of the obstacles, and therefore asking to update the documentation.
Regards Marco