Function CountRevisions(Rng As Range) As Long
Dim i As Long, j As Long
With Rng
  For i = 1 To .Revisions.Count
    If .Revisions(i).Type = wdRevisionInsert Then
      j = j + .Revisions(i).Range.ComputeStatistics(wdStatisticWords)
    End If
  Next
End With
CountRevisions = j
End Function