Win8 Strawberry 5.8.9.5 (32) Wed 11/25/2020 22:12:13 C:\@Work\Perl\monks >perl use strict; use warnings; my $pattern = '(testing)'; my $replacement = 'New \U$1'; my $flags = 'i'; my $value = 'My Testing Text'; ### $replacement =~ s/\\/\\\\/g; print "replacement '$replacement' \n"; eval "\$value =~ s/$pattern/$replacement/$flags"; print "$value\n"; ^Z replacement 'New \U$1' My New TESTING Text