How about this expression
(From d In DtBuild.AsEnumerable
Group d By k=d("Column Name").toString.Trim Into grp = Group
Let ra = New Object(){k,grp.First()(1)}
Select r = DtOutput.Rows.Add(ra)).CopyToDataTable
Check out the XAML file
Duplicate&Sum.xaml (9.1 KB)
Regards
Gokul