True, it won't work this way, but this quick test under the Perl debugger show that it might be feasible with a slight syntax tweak and one further step to process it. Here, I am passing the replacement string with \n to my debugger session: 
$ perl -de 42 foo\\n

Loading DB routines from perl5db.pl version 1.33
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(-e:1):   42
  DB<1> $c = shift;

  DB<2> x $c
0  'foo\\n'
  DB<3> $c =~ s|\\n|\n|;

  DB<4> x $c
0  'foo
'
  DB<5>

[download]
So, this seems to work, although it might not be the most elegant construct. Of course, it also assumes that you know when writing your program beforehand, you might need some newline characters to be reprocessed.

In reply to Re^3: Regex stored in a scalar by Laurent_R
in thread Regex stored in a scalar by OtakuGenX

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