I've just added the following code to my web site:
http://www.contextures.com/xlcomments03.html#OldName
The code will replace the old name with the new name, in the comment,
and in the status bar. If there are several names to replace, you could
run the macro as often as required, using a different "Old Name" each time.
'===============================
Sub ChangeCommentName()
'replaces old names in comments
'deletes and reinserts comments
' so new name appears in status bar
Dim ws As Worksheet
Dim cmt As Comment
Dim strOld As String
Dim strNew As String
Dim strComment As String
strNew = "New Name"
strOld = "Old Name"
Application.UserName = strNew
For Each ws In ActiveWorkbook.Worksheets
For Each cmt In ws.Comments
strComment = Replace(cmt.text, strOld, strNew)
cmt.Delete
cmt.Parent.AddComment text:=strComment
Next cmt
Next ws
End Sub
'================================