VBA中动态生成的控件

经上次发帖求助，自动创建了ComboBox控件

    Set mcolCombos1 = New Collection

    For i = 1 To 5

        Dim ctlCombo1 As ComboBox

        Set ctlCombo1 = Frame1.Controls.Add("Forms.combobox.1", "modular subbce" & i, True)

         

        With ctlCombo1

            .Left = 200

            .Top = 30 + (i - 1) * 50 + 6

            .Width = 120

            .Height = 20

            .AddItem "M  5/2 Monostable"

            .AddItem "B  5/2 Bistable"

        End With

         

        Dim objMyCombo1 As MyCombo

        Set objMyCombo1 = New MyCombo

        

        Set objMyCombo1.mctlCombo = ctlCombo1

        objMyCombo1.mlngIndex = i

         

        mcolCombos1.Add objMyCombo1

    Next i

此外自己创建了几个TextBox控件

Dim oTX As Control

    Dim i As Integer

    With UserForm1

        For i = 1 To 5        

            Set oTX = Frame1.Controls.Add("Forms.textbox.1", "Txt" & i, True)

            With oTX

                .Left = 100

                .Top = 30 + (i - 1) * 50 + 6

                .Width = 80

                .Height = 20

            End With

        Next i

    End With

目的是用户自行选择窗体动态生成的ComboBox中的Additem值，选择完分别将值的代码部分显示在TextBox中，将解释保留在ComboBox中。如若选择"M 5/2 Monostable"则TextBox中显示为“M”，ComboBox中显示为“5/2 Monostable”。
由于水平有限，现有以下几个问题：
1.若为窗体控件很容易将两者区分，用窗体控件的change（）事件就可解决，但若为动态添加的控件无法进行操作。
2.曾尝试在类模块中加以处理，代码如下：

Option Explicit

 

Public WithEvents mctlCombo As ComboBox



Public mlngIndex As Long

Public mcolCombosVal1 As String

Public mcolCombosVal1x As String

 

Private Sub mctlCombo_Change()

    MsgBox mcolCombosVal1

    mcolCombosVal1x = mcolCombos(1).mctlCombo.Value

    mcolCombosVal1 = Mid(mcolCombosVal1x, 1, 1)

    UserForm1.Controls("Txt1").Text = mcolCombosVal1

    mcolCombos(1).mctlCombo.Value = Mid(mcolCombosVal1x, 4)

End Sub

运行时提示错误“对象变量或with变量块未设置”
不知是为何错误？请指导，水平有限敬请谅解，谢谢！