Comparing values in a range

You can accomplish what you you have started-the concatenation idea-in VBA.

Sub CompareRows()
Dim rw As Long, i As Long, j As Long, k As Variant, c As Range
rw = ActiveSheet.UsedRange.Rows.Count 'assume data starts from row1
For i = 1 To rw
For j = 1 To 10 'assuming 10 columns of data
k = k & Cells(i, j)
Next
Cells(i, 11).Value = k
k = ""
Next

Set rng = Range(("K1"), Cells(Rows.Count, "K").End(xlUp))
For Each c In rng
If Application.CountIf(rng, c) > 1 Then
c.Offset(0, 1) = "Duplicate value"
End If
Next

End Sub

Jeff,

Here's a similar approach.

Sub sj()
    Dim r       As Excel.Range
    Dim iRow    As Long
    Dim iCol    As Long
    Dim iDup    As Long
    Dim asCat() As String

    Set r = Sheets("Record").UsedRange
    
    For iRow = 1 To r.Rows.Count
        ReDim Preserve asCat(1 To iRow)
        For iCol = 1 To r.Columns.Count
            asCat(iRow) = asCat(iRow) & r(iRow, iCol).Text
        Next iCol
        iDup = WorksheetFunction.Match(asCat(iRow), asCat, 0)
        If iDup < iRow Then
            Union(r.Rows(iDup), r.Rows(iRow)).Select
            MsgBox "Duplicates!"
        End If
    Next iRow
End Sub

BTW, the fact that the catenations are the same doesn't mean that the rows are identical;

12, 34

and

123, 4

catenate to the same result ...