CB_SETITEMDATA
wParam = (WPARAM) index; /* item index */
lParam = (LPARAM) (DWORD) dwData; /* item data */
An application sends a CB_SETITEMDATA message to set the 32-bit value associated with the specified item in a combo box.
index
Value of wParam. Specifies the zero-based index to the item.
dwData
Value of lParam. Specifies the new value to be associated with the item.
The return value is CB_ERR if an error occurs.
If the specified item is in an owner-draw combo box created without the CBS_HASSTRINGS style, this message replaces the 32-bit value that was contained in the lParam parameter of the CB_ADDSTRING or CB_INSERTSTRING message that added the item to the combo box.
CB_ADDSTRING, CB_GETITEMDATA, CB_INSERTSTRING