I'm sure there has to be a better way to do this (read: this could be way off the mark), but assuming you're referring to Crypt::RC4, try the following:

use Crypt::RC4;

my $key       = "abcdefghijklm";
my $plaintext = "Hello, World!";

my $encrypted = RC4($key, $plaintext);

print $encrypted, "\n";

my @characters;

for (split //, $encrypted) {
    push @characters, ord($_);
}

print @characters, "\n";
$encrypted = "";

for (@characters) {
    $encrypted .= chr($_);
}

print $encrypted, "\n";

my $decrypted = RC4($key, $encrypted);

print $decrypted, "\n";
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This basically just uses ord to return the numeric values of the encrypted string and place them in @characters. Probably not what you're looking for, but it can't hurt (can it? ;). I'm also curious, why exactly do you want to do this?