New Post: Reading Specific Columns or other ideas?

You could also use Linq magic with the DataTable:

var records = from a in _dataTable.AsEnumerable()
                  where a.Field<String>("Column1") == "SomeValue"
                  select a;

I like the DataTable data structure, even if it is a little passe with some developers. And I think it lends itself quite well as a wrapper for the Excel data format (columns, rows, etc).