As I told you in the chatterbox, you need File::Copy - which is a standard part of the Perl distribution.

use File::Copy;

copy('/home/bla/bla.ent', '/home/sla/sla')
  or die "Copy failed: $!";
[download]

It's also worth pointing out that this is a FAQ (see How can I copy a file?) When you're looking for help with Perl programming, it's always worth looking in the FAQ.