'Schleife über Tabellen-Zeilen 
For Each row As DataRow In ds.Tables(0).Rows
    '.....  
Next row

For rowindex As Integer = 1 To ds.Tables(0).Rows.Count - 1
    'zusätzliche Zeile einfügen
    Dim row As DataRow = ds.Tables(0).Rows(rowindex)
    '.....
Next rowindex