Hi,
How about the following expression?
targetDataRow = dt.AsEnumerable().OrderBy(Function(r) CDbl(System.Text.RegularExpressions.Regex.Match(r("Column1").ToString,"....$").Value)).Last()
OR
strVar = dt.AsEnumerable().OrderBy(Function(r) CDbl(System.Text.RegularExpressions.Regex.Match(r("Column1").ToString,"....$").Value)).Last.Item("Column1").ToString
Regards,