Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Application.Intersect(Target, Range("Data_Range")) Is Nothing Then
Range("Data_Range").Interior.Color = xlNone
Exit Sub
End If
Dim duplicates As Boolean
Dim dr As Range
Set dr = Range("Data_Range")
Dim min_row As Long
min_row = dr.Row
Dim data_array As Variant
data_array = dr.Value
dr.Interior.Color = xlNone
row_num = Target.Row - min_row + 1
For i = LBound(data_array, 1) To UBound(data_array, 1)
If data_array(i, 1) = Target And row_num <> i Then
duplicates = True
dr.Cells(1, 1).Offset(i - 1).Interior.Color = vbYellow
End If
Next
If duplicates Then
Target.Interior.Color = vbYellow
Else
MsgBox "No duplicates for this data ..."
End If
End Sub