Sub aaa()
  Dim aFN As Footnote, aRng As Range, aRngRef As Range, sCode As String
  For Each aFN In ActiveDocument.Footnotes
    Set aRng = aFN.Range
    With aRng.Find
      .ClearFormatting
      .Text = ""
      .Style = "MyStyle"
      If .Execute Then
        Set aRngRef = aFN.Reference
        aRngRef.Collapse wdCollapseEnd
        sCode = "TC """ & aRng.Text & """ \l 1 "
        ActiveDocument.Fields.Add Range:=aRngRef, Text:=sCode
      End If
    End With
  Next aFN
  
  Set aRng = ActiveDocument.Range
  aRng.InsertParagraphAfter
  aRng.Collapse wdCollapseEnd
  sCode = "TOC \f "
  ActiveDocument.Fields.Add Range:=aRng, Text:=sCode
End Sub