If you look at the link address in English it ends R2C2:R5C5
The R & C stand for Row and Column - Row2,Column2 >>Row5,Column5
The German for Row is Zeile and for Column is Spalte
So (not very clever of MSFT) in German the link ends Z2S2:Z5S5
Sub G2E()
    Dim regX As Object
    Dim osld As Slide
    Dim oshp As Shape
    Dim b_found As Boolean
    Dim strLink As String
    On Error Resume Next
    Set regX = CreateObject("vbscript.regexp")
    With regX
        .Global = True
        .Pattern = "Z(\d)S(\d)"
    End With
    For Each osld In ActivePresentation.Slides
        For Each oshp In osld.Shapes
               strLink = oshp.LinkFormat.SourceFullName
                    If Err = 0 Then
                        b_found = regX.Test(strLink)
                        If b_found = True Then
                            strLink = regX.Replace(strLink, "R$1C$2")
                           oshp.LinkFormat.SourceFullName = strLink
                        End If
                    End If
        Next oshp
    Next osld
    Set regX = Nothing
End Sub