This User Defined function does what you want. Call it with, for example,
=FIND2(A1:AZ1)

Function find2(myrange)
 For Each mycell In myrange
   If mycell.Value = "Q3 2007T" Then
     mycount = mycount + 1
   End If
   If mycount = 2 Then
     Set mc = mycell
     myaddress = mc.Address()
     Exit For
   End If
 Next
 If mycount < 2 Then
   find2 = "found " & mycount
 Else
   find2 = myaddress
 End If
End Function

New to VBA? See David McRitchie's site on "getting started" with VBA

http://www.mvps.org/dmcritchie/excel/getstarted.htm
best wishes