Set myShape = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Shapes(1)

Sub BuildAppendixA4(ByRef strArg As String)

Dim aDoc As Document, aSec As Long, aRng As Range, bRng As Range, bSec As Long
Dim myShape As Shape
Dim oTemplate As Template

    'On Error Resume Next
    aSec = Selection.Information(wdActiveEndSectionNumber)
    Set aDoc = ActiveDocument
    Set aRng = aDoc.Sections(aSec).Range
    Set oTemplate = ActiveDocument.AttachedTemplate
  
    'Put cursor at end of current section
    aRng.Collapse Direction:=wdCollapseEnd
  
     Selection.InsertBreak Type:=wdSectionBreakNextPage
     
     'Make sure the view is correct
     If ActiveWindow.View.SplitSpecial <> wdPaneNone Then
         ActiveWindow.Panes(2).Close
     End If
     If ActiveWindow.ActivePane.View.Type = wdNormalView Or ActiveWindow. _
         ActivePane.View.Type = wdOutlineView Then
         ActiveWindow.ActivePane.View.Type = wdPrintView
     End If
     
     'Turn off link to previous in case previous appendix isn't A4 Portrait
     ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageHeader
     With Selection.HeaderFooter
     .LinkToPrevious = Not Selection.HeaderFooter.LinkToPrevious
     End With
     
     'Advance selected section by one, which puts us in the newly-created section
     aSec = aSec + 1
     
     'Set a new range which is the header of the new section, and set it to be a different first page
     Set bRng = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range
     aDoc.Sections(aSec).PageSetup.DifferentFirstPageHeaderFooter = True
     
     'Set it to be an A4 portrait page, in case the previous appendix wasn't A4 portrait
     With aDoc.Sections(aSec).PageSetup
         .Orientation = wdOrientPortrait
         .PageWidth = CentimetersToPoints(21)
         .PageHeight = CentimetersToPoints(29.7)
     End With
     
     'Delete anything in the header already, and insert the correct cover page jpeg from building blocks
     aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range.Delete
     oTemplate.BuildingBlockEntries("Appendix Cover").Insert Where:=bRng, RichText:=True
     
     'aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range.Select
    
     'Set the selection to be the appendix cover jpeg, which will be the only shape in the selected header
     Set myShape = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Shapes(1)
     
     'Make sure the A4 jpeg is the correct size and positioned correctly
     With myShape
         .WrapFormat.Type = wdWrapFront
         .LockAspectRatio = msoTrue
         .Width = CentimetersToPoints(21)
         .RelativeHorizontalPosition = wdRelativeHorizontalPositionPage
         .Left = wdShapeLeft
         .RelativeVerticalPosition = wdRelativeVerticalPositionPage
         .Top = wdShapeTop
     End With
     
     'Exit the header and insert the appendix heading text
     ActiveWindow.ActivePane.View.SeekView = wdSeekMainDocument
     
     Selection.Style = ActiveDocument.Styles("Heading 9")
     Selection.TypeText Text:=Chr(11) & "Appendix Name"
     Selection.TypeParagraph
     
     
     Select Case strArg
         Case "AppendixNextA4Portrait"
             Selection.InsertBreak Type:=wdPageBreak
             Selection.TypeParagraph
         Case "AppendixNextA3Portrait"
             Selection.InsertBreak Type:=wdSectionBreakNextPage
             ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageHeader
             With Selection.HeaderFooter
                 .LinkToPrevious = Not Selection.HeaderFooter.LinkToPrevious
             End With
             aSec = aSec + 1
             Set bRng = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range
             aDoc.Sections(aSec).PageSetup.DifferentFirstPageHeaderFooter = False
             With aDoc.Sections(aSec).PageSetup
                 .Orientation = wdOrientPortrait
                 .PageWidth = CentimetersToPoints(29.7)
                 .PageHeight = CentimetersToPoints(42)
             End With
         Case "AppendixNextA4Landscape"
             Selection.InsertBreak Type:=wdSectionBreakNextPage
             ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageHeader
             With Selection.HeaderFooter
                 .LinkToPrevious = Not Selection.HeaderFooter.LinkToPrevious
             End With
             aSec = aSec + 1
             Set bRng = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range
             aDoc.Sections(aSec).PageSetup.DifferentFirstPageHeaderFooter = False
             With aDoc.Sections(aSec).PageSetup
                 .Orientation = wdOrientLandscape
                 .PageWidth = CentimetersToPoints(29.7)
                 .PageHeight = CentimetersToPoints(21)
             End With
         Case "AppendixNextA3Landscape"
             Selection.InsertBreak Type:=wdSectionBreakNextPage
             ActiveWindow.ActivePane.View.SeekView = wdSeekCurrentPageHeader
             With Selection.HeaderFooter
                 .LinkToPrevious = Not Selection.HeaderFooter.LinkToPrevious
             End With
             aSec = aSec + 1
             Set bRng = aDoc.Sections(aSec).Headers(wdHeaderFooterFirstPage).Range
             aDoc.Sections(aSec).PageSetup.DifferentFirstPageHeaderFooter = False
             With aDoc.Sections(aSec).PageSetup
                 .Orientation = wdOrientLandscape
                 .PageWidth = CentimetersToPoints(42)
                 .PageHeight = CentimetersToPoints(29.7)
             End With
     End Select
        
    ActiveWindow.ActivePane.View.SeekView = wdSeekMainDocument
  
End Sub

Sub TestHeaderFloaters()
  Dim aH As HeaderFooter, aShp As shape, aSect As Section
  
  Debug.Print ActiveDocument.Sections(1).Headers(wdHeaderFooterPrimary).Shapes.Count
  
  For Each aSect In ActiveDocument.Sections
    For Each aH In aSect.Headers
      For Each aShp In aH.Shapes
        Debug.Print aSect.Index, aH.Index, aShp.Anchor.Information(wdActiveEndSectionNumber), aShp.AlternativeText
      Next aShp
    Next aH
  Next aSect
  
End Sub