int SetTopIndex( int nIndex );
nIndex
Specifies the zero-based index of the list-box item.
Ensures that a particular list-box item is visible.
The system scrolls the list box until either the list-box item appears at the top of the list box or the maximum scroll range has been reached.
LB_ERR if an error occurs.
CListBox::GetTopIndex, LB_SETTOPINDEX