var ctrlMan = m_Map.GetCtrlMan();
var layerMan = ctrlMan.GetLayerMan();
var util = m_Map.GetUtility();
var ctrlstate = ctrlMan.GetControlState();
var posLL = ctrlstate.GetLLCenter();
var x = posLL.GetX();
var y = posLL.GetY();
var ptlist = util.GetPointList();
var point = util.GetPoint(x, y-400);
ptlist.Add(point);
var obj = layerMan.FindLayer(1).FindObject(10);
if(obj)
{
obj.AddPointList(ptlist);
}