use strict;
my $str = 'But seeing them playing to seven- and eight-year-olds is beautiful
The country was in the uproar of pre- and then post-independence civil war but the mood here is most often joyous';
my $regex = qr/\b-(\s+(?:and|to|or)(?:\s+\w+)*\s+\w+(-\w[\w-]*))/mp;
my $subst = '\\2\\1';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html