Try this:

package Bob;
use Safe;
use Digest::MD5;

$cpt = new Safe;
$cpt->share('&alpha');

$str1 = 'print Digest::MD5::md5_hex("Jerrad"), "\n"';
$str2 = 'print "Hello World\n"';
sub alpha{ "Do things\n" };
sub beta { "Do other things\n" };

eval $str1;
eval $str2;
eval "print &alpha";
eval "print &beta";

$cpt->reval($str1);
$cpt->reval($str2);
$cpt->reval("print &alpha");
$cpt->reval("print &beta");
__END__
[download]

Yields:

26e30951791b6e173148f99d8b709c5b
Hello World
Do things
Do other things
Hello World
Do things
[download]

etc. etc. I never meant to imply it was easy as pie, just that it helped (made hard things possible ;-).