Sub FnR(Rng As Range)
Dim strFindText As String, strReplaceText As String, nSplitItem  As Long
strFindText = "northenn,westenn"
strReplaceText = "northern,western"
With Rng.Find
  .ClearFormatting
  .Replacement.ClearFormatting
  .Forward = True
  .Format = False
  .MatchCase = False
  .MatchWholeWord = False
  .Wrap = wdFindContinue
  For nSplitItem = 0 To UBound(Split(strFindText, ","))
    .Text = Split(strFindText, ",")(nSplitItem)
    .Replacement.Text = Split(strReplaceText, ",")(nSplitItem)
    .Execute Replace:=wdReplaceAll
  Next
End With
End Sub