Assuming you don't have a program named "60" (<grin>), it populates $! with a known error message, “No such file or directory”. Later, the line

$!=~/(.)(.).(.)(.)(.)(.)..(.)(.)(.)..(.)......(.)/

fetches some characters from that string. It then mangles and glues those characters together into a shell command, which is executed in the last ¾ of the fourth line.

Hope this helps....