Report风格的ListCtrl控件，当鼠标点击时，如何确定被点击单元的Item和subItem?

POSITION pos;
CRect rect;
int iItem;
int iSubItem;
iItem=m_nList.GetNextItem(-1,LVNI_SELECTED);
POINT pt;
GetCursorPos(&pt);
GetWindowRect(rect);
pt.x-=rect.left;
pt.y-=rect.top;
    
for ( int i=0, j=0; ; i++)
{
j+=GetColumnWidth(i);
if ( pt.x < j )
break;
}
    
iSubItem = i;