Help with highlighting rows based on identical values in multiple columns

Hi,

I am using the code below to highlight records where selected column (i.e. yx = column1)have identical values in two or more records. How do I modify it to the the same when I select multiple columns? For example If I select two columns (i.e. yx = column1, column2) from a list box I need to highlight records where values in both columns are identical in two or more records. This is third party Grid Control from ComponentOne.

 Dim cc As Integer = 0
        e.CellStyle.BackColor = DefaultBackColor
        e.CellStyle.ForeColor = DefaultForeColor
        Try
            Dim checkCols As String = yx

            If checkCols.Count > 0 Then

                Dim tempRow = C1Screen1.FocusedSplit.Rows.OfType(Of C1.Win.C1TrueDBGrid.BaseGrid.ViewRow).ToList()
                Dim flag As Boolean = False
                Dim origItem As String = ""
                For Each item As String In checkCols.Split(","c)
                    origItem = origItem + C1Screen1(e.Row, item.Trim("'"c)).ToString()
                Next
                For j As Integer = 0 To tempRow.Count - 1
                    Dim tempItem As String = ""
                    For Each item As String In checkCols.Split(","c)
                        tempItem = tempItem + C1Screen1(j, item.Trim("'"c)).ToString()
                    Next
                    If Not flag AndAlso e.Row <> j Then
                        If origItem = tempItem Then
                            flag = True
                        End If
                    End If
                Next
                e.CellStyle.BackColor = DefaultBackColor
                e.CellStyle.ForeColor = DefaultForeColor
                If flag Then
                    e.CellStyle.BackColor = Color.DarkGreen
                    e.CellStyle.ForeColor = Color.White
                    cc = 1
                    Exit Sub
                Else
                    e.CellStyle.BackColor = DefaultBackColor
                    e.CellStyle.ForeColor = DefaultForeColor
                    cc = 0
                End If
            End If
            '   C1Screen1.Refresh()
            If cc <> 1 Then
                C1Screen1.Refresh()
                ' MsgBox("No Matches Found")
                'Exit Sub
            End If
        Catch
            ccc = 1
            Exit Sub

        End Try

Thanks,

Victor