用自定义值替换MailEnvelop中的复选框

Question

我需要将文档作为电子邮件正文发送。该文档包含几个{ FORMCHECKBOX }字段，可以选择是否选择。现在，无论何时我实际发送电子邮件，都根本不包括这些复选框。由于这个问题，我很想根据选择将复选框替换为“是”或“否”。

我找到了这段代码，以替换所有复选框，但它并不适合实际选择：

Sub ChkBxClr()
    Dim i As Long, Rng As Range
    With ActiveDocument
        For i = .FormFields.Count To 1 Step -1
            With .FormFields(i)
                If .Type = wdFieldFormCheckBox Then
                    Set Rng = .Range
                    .Delete
                    Rng.Text = "[__]"
                End If
            End With
        Next
        Set Rng = Nothing
    End With
End Sub

此代码还更改了整个文档，而不仅仅是电子邮件正文，我想防止这种情况。

整体代码：

Sub SendEmail()

    Dim Subject As String
    Dim From As String

    On Error Resume Next

    Selection.GoTo What:=wdGoToBookmark, Name:="From"
    From = Selection.Text

    Subject = "Title"

    Call ChkBxClr

    ActiveWindow.EnvelopeVisible = True
    With ActiveDocument.MailEnvelope.Item
        .To = "<some mail address>"
        .Subject = Subject
        .Send
    End With

End Sub

Sub ChkBxClr()
    Dim i As Long, Rng As Range
    With ActiveDocument
        For i = .FormFields.Count To 1 Step -1
            With .FormFields(i)
                If .Type = wdFieldFormCheckBox Then
                    Set Rng = .Range
                    .Delete
                    Rng.Text = "[__]"
                End If
            End With
        Next
        Set Rng = Nothing
    End With
End Sub

问题是，如何根据选择内容显示电子邮件正文中的复选框或用文本替换复选框（最好仅在邮件正文中）？