How to edit the custom property of a configuration ?

I tried the following code,but failure. The code has not error happend.

Function Edit_Part_CP
    On Error GoTo ErrMsg

    Dim swDocMgr As SwDocumentMgr.SwDMApplication
    Dim swDoc As SwDocumentMgr.SwDMDocument5
    Dim classfac As SwDocumentMgr.SwDMClassFactory
    Dim swcfg As SwDocumentMgr.SwDMConfiguration   ' I tried SwDMConfiguration1~7,but failure.

    Dim I As Integer

           
    Set classfac = CreateObject("SwDocumentMgr.SwDMClassFactory")
    Set swDocMgr = classfac.GetApplication("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx") 'Specify your license key
    Set swDoc = swDocMgr.GetDocument(Me.FilePath, swDmDocumentUnknown, True, swDmDocumentOpenErrorNone)
   
    If Not swDoc Is Nothing Then
    Set swcfg = swDoc.ConfigurationManager.GetConfigurationByName(Me.Version)
   

    swcfg.SetCustomProperty "Name", "try"  ' This line is noneffective.

    swDoc.Save
    swDoc.CloseDoc
    End If

    Set swDoc = Nothing
    Set swDocMgr = Nothing
    Set classfac = Nothing
    Set swcfg = Nothing
    Exit Function

ErrMsg:
   
    MsgBox Me.FilePath & vbCrLf & Err.Description
   

End Function