I've had good results with
Function noDups(myStr As String) As String
Dim myA() As String, myB As String, myI As Integer
myA = Split(Trim(myStr), ",")
For myI = LBound(myA) To UBound(myA)
If InStr(myB, LTrim(myA(myI))) = 0 Then
myB = myB & "," & myA(myI)
End If
Next myI
noDups = Mid(myB, 2)
End...