try following code

Code:
--------------------

Private Sub mySub()
Dim row As Integer, col As Integer
row = 1
col = 1
Dim str As String
Dim i As Integer

While Sheet1.Cells(row, col).Value < ""
'*F0123450 --- *F*123450*
str = Sheet1.Cells(row, col).Value

If Mid(str, 3, 1) = "0" Then
str = Left(str, 2) & "*" & Mid(str, 4, Len(str))
Sheet1.Cells(row, col).Value = str
End If

row = row + 1
Wend
End Sub

--------------------



Chris
------
Convert your Excel spreadsheet into an online calculator.
http://www.spreadsheetconverter.com




--
Chris Bode