DataTable sort by sum of columns

I want to order a datatable by the sum of it's columns, e.g.

dtSummary.DefaultView.Sort = "(Calls Closed + New Calls Triaged + Overdue Calls Triaged) As开发者_Go百科c";

I guess I could do this by adding an extra column and computing the sum values before the sort, but wondered if there was a simpler way to acheive this.