OK. I got this to work :

 Public Sub main()
        Dim o As New DataTable
        o.Columns.Add("Sight", GetType(String))
        o.Columns.Add("Account", GetType(String))
        o.Columns.Add("Amount", GetType(Double))
        o.Columns.Add("Amount1", GetType(Double))

        o.Rows.Add("S1", "A1",1,2)
        o.Rows.Add("S2", "A1",2,4)
        o.Rows.Add("S1", "A1",3,6)
        o.Rows.Add("S2", "A1",4,8)
        o.Rows.Add("S1", "A1",5,10)
        o.Rows.Add("S2", "A1",6,12)
        Dim q
        q = From record In o _
            Group By sight = record("Sight") & record("Account")
            Into totAmount = Sum(record.Field(Of Double)("Amount")) _
            , totAmount1 = Sum(record.Field(Of Double)("Amount1"))
            Order By totAmount1
            Select sight, totAmount, totAmount1
        For Each o1 In q
            Debug.Print(o1.ToString)
        Next
end sub

Any chance that I get Sight and Account separately in my output in this configuration?

Thanks for any light and kind regards,

Marc