Hmmm, I'm not exactly sure what it is that you are trying to do but you may want to investigate the Safe module for the evaluation of supplied Perl code. This module allows you to evaluate Perl code in a contained compartment where restrictions can be imposed on allowed and disallowed operators - This can be very important where the code is derived from a potentially unsafe source.

 

perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'