For SQL Server, a generic way to go by row number is as such:
SET ROWCOUNT @row --@row = the row number you wish to work on.
For Example:
set rowcount 20 --sets row to 20th rowselect meat, cheese from dbo.sandwich --select columns from table at 20th rowset rowcount 0 --sets rowcount back to all rows
This will return the 20th row's information. Be sure to put in the rowcount 0 afterward.