int SetItemData( int nIndex, DWORD dwItemData );
nIndex
Contains a zero-based index to the item to set.
dwItemData
Contains the new value to associate with the item.
Sets the 32-bit value associated with the specified item in a combo box.
CB_ERR if an error occurs.
CComboBox::GetItemData, CB_SETITEMDATA, CComboBox::AddString, CComboBox::InsertString