I have a very large number of files with very similar names: row1col1.txt, row1col2.txt, row1col3.txt, row1col4.txt......
I'd like to make copies of them all and change the names to row2col1.txt, row2col2.txt, row2col3,txt, row2col4.txt......
Using the cp command in shell script, how can I do it efficiently?