It is only possible to draw a polygon. For example this draws a star:
ImageEnVect1.SetObjPolylinePoints(-1, [Point(0,65), Point(50,80), Point(65,130), Point(80,80), Point(130,65), Point(80,50), Point(65,0), Point(50,50), Point(0,65)]);
ImageEnVect1.ObjKind[-1] := iekPOLYLINE;
ImageEnVect1.AddNewObject();