hwnd (HWND) - input
index (LONG) - input
The units of index are bytes. Valid values are zero through (cbWindowData -4), where cbWindowData is the parameter in WinRegisterClass that specifies the number of bytes available for application-defined storage. Any of the following QWL_* values can be specified:
QWL_HMQ
WC_FRAME (includes dialog windows) WC_COMBOBOX
WC_BUTTON
WC_MENU
WC_STATIC
WC_ENTRYFIELD
WC_LISTBOX
WC_SCROLLBAR
WC_TITTLEBAR
WC_MLE
WC_SPINBUTTON
WC_CONTAINER
WC_SLIDER
WC_VALUESET
WC_NOTEBOOK
The default push button is the one that sends its WM_COMMAND message when the enter key is pressed.
flData (ULONG) - input
This is done under the control of the flMask parameter.
flMask (ULONG) - input
A "1" bit indicates that the corresponding bit of the flData parameter is to be stored into the window word. A "0" bit indicates that the corresponding bit of the flData parameter is to be ignored in the storing operation; the value of that bit position in the window word is unaltered.
rc (BOOL) - returns
TRUE