Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de writes:
I don't know if this global approach is valid, but at least it helped me to get winhlp32 working called with WinHelpA from an application. In what other way can we cope with user defined messages and their related structures in inter-process SendMessage?
We can't. User messages cannot pass data around, WinHelpA will need to do that differently. The best way to find out how is probably to watch winhlp32 with a message spy under Windows.