use strict;
use warnings;
use Text::ParseWords;
use Data::Dumper;

my $marked = 'Jack and Jill went #up the hill# to fetch a #pail of water#.';
$marked =~ s/#/"/g;
my @words = shellwords($marked);
print Dumper(\@words);

__END__
$VAR1 = [
          'Jack',
          'and',
          'Jill',
          'went',
          'up the hill',
          'to',
          'fetch',
          'a',
          'pail of water.'
        ];