An application sends an LB_SETSEL message to select a string in a multiple-selection list box.
LB_SETSEL
wParam = (WPARAM) (BOOL) fSelect; // selection flag
lParam = (LPARAM) (UINT) index; // item index
If an error occurs, the return value is LB_ERR.
Use this message only with multiple-selection list boxes.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
List Boxes Overview, List Box Messages, LB_GETSEL, LB_SELITEMRANGE