use strict;
use warnings;
use Text::Unaccent::PurePerl qw(unac_string);
use utf8;

my $string = 'côte';
my $rstring;
for ($string) {
	$rstring = mixedregex($_);
}
print "$string $rstring\n";
my $blot = unac_string("UTF-8", $rstring);
print "$string $rstring $blot\n";

sub mixedregex {
	s[([0-7]{3})][chr oct $1]egr;
}