An application sends a CB_SETEDITSEL message to select characters in the edit control of a combo box.
CB_SETEDITSEL
wParam = 0; // not used; must be zero
lParam = MAKELPARAM((ichStart), (ichEnd); // start and end position
If the message succeeds, the return value is TRUE. If the message is sent to a combo box with the CBS_DROPDOWNLIST style, it is CB_ERR.
The positions are zero-based. The first character of the edit control is in the zero position. The first character after the last selected character is in the ending position. For example, to select the first four characters of the edit control, use a starting position of 0 and an ending position of 4.
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.
Combo Boxes Overview, Combo Box Messages, CB_GETEDITSEL