Maybe you are thinking of the charnames pragma?

#!/usr/bin/perl

use warnings;
use strict;
use charnames();

my $string = 'Lo1';

print string_to_text($string);

sub string_to_text{
    my @chars;
    push @chars, charnames::viacode(ord($_)) for split //, $_[0];
    return join ', ', @chars;
}
[download]

Yields...

LATIN CAPITAL LETTER L, LATIN SMALL LETTER O, DIGIT ONE