Macro to modify header in multiple word documents

[macropod]

For what's indicated in your attachments, add the following macro to your 'new header' document. Do not store that file in the folder to be processed:

Sub UpdateDocumentHeaders()
    Application.ScreenUpdating = False
    Dim strFolder As String, strFile As String, StrRef As String, StrTtl As String
    Dim wdDocTgt As Document, wdDocSrc As Document, Sctn As Section, HdFt As HeaderFooter
    strFolder = GetFolder
    If strFolder = "" Then Exit Sub
    Set wdDocSrc = ActiveDocument
    strFile = Dir(strFolder & "\*.doc", vbNormal)
    While strFile <> ""
        Set wdDocTgt = Documents.Open(FileName:=strFolder & "\" & strFile, _
        AddToRecentFiles:=False, Visible:=False)
        With wdDocTgt
            For Each Sctn In .Sections
                For Each HdFt In Sctn.Headers
                    With HdFt
                        If .LinkToPrevious = False Then
                            If .Range.Tables.Count = 1 Then
                                With .Range.Tables(1).Range
                                    StrRef = Split(Split(.Cells(2).Range.Text, ":")(1), Chr(13))(0)
                                    StrTtl = Split(Split(.Cells(7).Range.Text, ":")(1), Chr(13))(0)
                                End With
                                .Range.FormattedText = _
                                  wdDocSrc.Sections.First.Headers(wdHeaderFooterPrimary).Range.FormattedText
                                With .Range.Tables(1).Range
                                  .Cells(2).Range.InsertAfter StrRef
                                  .Cells(4).Range.InsertAfter StrTtl
                                End With
                            End If
                        End If
                    End With
                Next
            Next
            .Close SaveChanges:=True
        End With
        strFile = Dir()
    Wend
    Set wdDocSrc = Nothing: Set wdDocTgt = Nothing
    Application.ScreenUpdating = True
End Sub
 '
Function GetFolder() As String
    Dim oFolder As Object
    GetFolder = ""
    Set oFolder = CreateObject("Shell.Application").BrowseForFolder(0, "Choose a folder", 0)
    If (Not oFolder Is Nothing) Then GetFolder = oFolder.Items.Item.Path
    Set oFolder = Nothing
End Function