Special hardware buttons are sent to a window via the wxEVT_HOTKEY event under Smartphone and PocketPC. You should first register each required button with wxWindow::RegisterHotKey, and unregister the button when you're done with it. For example:
win->RegisterHotKey(0, wxMOD_WIN, WXK_SPECIAL1); win->UnregisterHotKey(0);
You may have to register the buttons in a wxEVT_ACTIVATE event handler since other applications will grab the buttons.
There is currently no method of finding out the names of the special buttons or how many there are.