ok, but i do it on script ?
What environment does "on script" connote? The program in question is invoked by "some something", and that "some something"'s STDERR must be redirected to the error log. The notation I gave is for bash (and sh, korn shell, zsh and others). Check the documentation of that "some something" about how to redirect its STDERR.
If that "some something" is another instance of perl, see open about how to redirect STDERR. You might want to localize that redirection.
perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'
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