Sub AppendixParens()
'   Charles Kenyon using code from Graham Mayor
'   October 21, 2021
'   https://www.msofficeforums.com/word/47835-putting-parentheses-around-sequence-number-caption-label.html
    Dim oStory As range, oFld as Field
    On Error Resume Next
    For Each oStory In ActiveDocument.StoryRanges
        Do
            For Each oFld In oStory.Fields
                If oFld.Type = wdFieldSequence Then
                    If InStr(1, oFld.Code, "Appendix") > 0 Then
                        oFld.Result.InsertAfter ")"
                        oFld.Result.InsertBefore "("
                    End If
                End If
            Next oFld
        Loop Until oStory Is Nothing
     Next
    Set oFld = Nothing
    Set oStory = Nothing
    On Error GoTo -1
 End Sub