How to return only one record from a dataset

Public Function ReadPolicyStep1(ByVal custnum As String, ByVal symb0l As String, ByVal policynum As String) As DataRow

    Dim con As OdbcConnection = New OdbcConnection(_connString)
    Dim cmd As OdbcCommand = New OdbcCommand("SELECT CUST0NO, SYMBOL, POLICY0NUM, MODULE, TYPE0ACT FROM CCC00200 WHERE CUST0NO = ? AND SYMBOL = ? AND POLICY0NUM = ? ORDER BY MODULE DESC", con)

    cmd.Parameters.AddWithValue("@custnum", custnum)
    cmd.Parameters.AddWithValue("@symb0l", symb0l)
    cmd.Parameters.AddWithValue("@policynum", policynum)

    cmd.CommandType = CommandType.Text

    Dim da As New OdbcDataAdapter(cmd)
    Dim ds As New DataSet()

    Using da
        da.Fill(ds)
    End Using

   If ds.Tables(0).Rows.Count > 0 Then
        Return Nothing
    Else
        Return ds.Tables(0).Rows(0)
    End If

End Function

Dim cmd As OdbcCommand = New OdbcCommand("SELECT top 1 CUST0NO, SYMBOL, POLICY0NUM, MODULE, TYPE0ACT FROM CCC00200 WHERE CUST0NO = ? AND SYMBOL = ? AND POLICY0NUM = ? ORDER BY MODULE DESC", con)