Find missing data in columns ignoring blanks, separated by semicolon

Hi..

Try this.. no formulas needed.. just paste your value sin column A and B..

Private Sub CommandButton1_Click()
   Dim x, j As Long, jj As Long
   With Range("A1").CurrentRegion
   x = .Offset(1).Resize(.Rows.Count - 1)
   End With
    With CreateObject("scripting.dictionary")
        For j = 1 To UBound(x)
            x0 = .Item(x(j, 2))
        Next
        For jj = 1 To UBound(x)
            If Not .Exists(x(jj, 1)) Then
                If Cells(2, 3).Value = "" Then
                    Cells(2, 3).Value = x(jj, 1)
                Else: Cells(2, 3).Value = Cells(2, 3).Value & ";" & x(jj, 1)
                End If
            End If
        Next jj
    End With
End Sub

Try the attached.