CB_SETITEMDATA
wParam = (WPARAM) index; /* item index */
lParam = (LPARAM) (DWORD) dwData; /* item data */
An application sends a CB_SETITEMDATA message to set the doubleword 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.