BCGControlBar Pro for MFC
BOOL CBCGPToolbarComboBoxButton::SelectItem ( LPCTSTR  lpszText)

Searches the list of items of a combo box button and selects one of them according to the specified string.

Nonzero if the item was found and selected; otherwise 0.

Searches for an item in the list box of a combo box by string, and if the item is found, selects it in the list box and copies its text to the edit control.

lpszTextSpecifies the text to search for. The item that was assigned this text is selected.