在vb.net中如何调用cad程序

老师上课用的是vb6.0的程序调用cad。求各位大神帮忙看看在中应该是什么？？？
Dim AcadApp As AcadApplication
Dim AcadDoc As AcadDocument, AcadDoc1 As AcadDocument
Dim Arecord As Recordset
Dim Plan_Coor(10) As Coor_G
Dim pointObj As AcadPoint
Dim textObj As AcadText
Dim layerObj As AcadLayer
Dim circleObj As AcadCircle
Dim lineObj As AcadLine