MM_SELECTITEMBYPOS

#define MM_SELECTITEMBYPOS    0x019e

Set selection state by its position.

mp1

MIT_FIRST

first item in the menu

MIT_LAST

last item in the menu

MIT_NONE

deselect all items in the menu

other

position of item in the menu.

mp2

SHORT1FROMMP

reserved and set to zero

SHORT2FROMMP

TRUE = dismiss the menu and post WM_COMMAND,
       WM_SYSCOMMAND or WM_HELP message
FALSE = do not dismiss the menu

Returns TRUE if the selection was made, or MIT_NONE was specified. Returns FALSE if the item is not selectable, the item was deselected, or MIT_NONE was not specified.

This message will set the selection state in the specified menu. If the item being selected is in a submenu that is in a submenu that is not currently displayed, then the menu is summoned and displayed. If the item selected is in a submenu, the item is selected and the selection state of the menu owning the submenu is also set. This process continues up the menu hierarchy until the top-level menu is reached.

(Source: newsgroup)