Here's some generic LINQ code that should work (you have to replace the column comparison stuff with appropriate values from your own code):
var results = (from record in dataTable
where record.column == somevalue
select record).ToList();
...but I have to ask - why bother with LINQ when a simple and maintainable non-LINQ solution works fine and will probably be better performing beisdes? If this is for a work project, close the file and move on to the next task.