VB编程,对话框使用acedGetXXX函数和ACAD交互

Private Sub Form_Load()Dim obj_Acad As Object, obj_Doc As Object, obj_ModelSpace As Object, obj_Util As Object
Set obj_Acad = GetObject(, ".application")
If Err Then
   Err.Clear
   On Error Resume Next
   Set obj_Acad = CreateObject("autocad.application")
   If Err Then
      Err.Clear
      MsgBox "不能运行AutoCAD,请检查是否安装！", vbOKOnly, "警告！"
      Exit Function
      End If
End If
obj_Acad.Visible = True
Set obj_Doc = obj_Acad.ActiveDocument
Set obj_Util = obj_Doc.Utility
Set obj_ModelSpace = obj_Doc.ModelSpace
End Sub
'获取点按钮
Private Sub Getpoint_Click()
            Dim pt As Variant
            Do While CAD.Getpoint(pt, vbCrLf & "获取点:")
               If IsNull(pt) Then
                    'lop1 = False
                Else
                    CAD.Addcircle pt, 100
                End If
            Loop
End SubPublic Function Getpoint(ByRef rePnt As Variant, ByRef inputString As String, Optional Msg As String, Optional pt As Variant) As Boolean
'On Error Resume Next
ActiveDoc
rePnt = obj_Util.Getpoint(, Msg)
If Err Then
         If Err.Number = -2145320928 Then
             'Dim inputString As String
             Err.Clear
             inputString = ThisDrawing.Utility.GetInput
             'GetPoint = True
         Else
         Getpoint = False
             MsgBox "getpoint错误: " & Err.Description
             Err.Clear
         End If
    Else
        ' Display point coordinates
        'MsgBox "The WCS of the point is: " & reVal(0) & ", " & reVal(1) & ", " & reVal(2), , "GetInput Example"
        Getpoint = True
    End If
End Function
Public Function GetEntity0(ByRef Retobj As Variant, ByRef inputString As String, Optional Msg As String = "") As Boolean
On Error Resume Next
Dim Point As Variant
ActiveDoc
 obj_Util.GetEntity Retobj, Point, Msg
If Err Then
         If Err.Number = -2145320928 Then
         ' One of the keywords was entered
             Err.Clear
             inputString = ThisDrawing.Utility.GetInput
         Else
             MsgBox "GetEntity0错误: " & Err.Description
             Err.Clear
             GetEntity0 = False
         End If
    Else
        GetEntity0 = True
    End If
End Function
Public Function Addcircle(ByRef Center As Variant, ByVal Radius As Double) As Object
Dim obj_circle As Object       '定义圆对象
Dim newstr As String
On Error Resume Next
If Not boo Then
  MsgBox "请先生成autocad程序对象", vbOKOnly, "autocad程序对象？"
  Exit Function
  End If
Set obj_circle = obj_ModelSpace.Addcircle(Center, Radius)
Set Addcircle = obj_circle
End Function

*.Utility.GetPoint(, "Enter a point: ")
*.Utility.GetDistance(, "Enter distance: ")
想达到效果：
1、在非模态状态下，本来是使用getpoint的，但还是getpoint的命令状态下，就按获取距离按钮，这时就取消原命令而运行GetDistance
或
2、在非模态状态下，本来是使用GetDistance的，但还是GetDistance的命令状态下，就按获取点按钮，这时就取消原命令而运行getpoint
本意是想取消原命令，但实际却变成嵌套了，即运行完GetDistance后，还会要求选取一个点。
如何取消当前的命令呢(getXXXXX)