How To Sort By Columns In A Datatable

I currently have a datagridview that is built from a datatable So lets say we have 6 columns

A B C D E G

So the users will select there data from another program and paste into the the table. So lets assume that the data that is pasted is; (the column names are automatically put in)

A B C D E G
123 456 789 101 112 134

So the table will now look like following (I remove the first row because its the same as the column name)

A B C D E G
A B C D E G
123 456 789 101 112 134

My problem is that the users can rearrange thier tables(column index) so lets say user A has the table in this format

A B D E C G
123 456 101 112 789 134

So when they paste into the program, it will look like

A B C D E G
A B D E C G
123 456 101 112 789 134

So now "C" "D" "E" are incorrect and i need to swap those columns to be the same as the column name. I'm not sure how to attack this problem.My thoughts were to paste the data as is, than see what the first row in each column equals.so if it equals "A" assign it an index 0

B 1
C 2

This seems theres too many steps and will slow down the app...