The easiest way to do it is pass the info in on the commandline, instead of trying to run the commands in interactive mode (which can be done, but involves much more work) for all the options to nslookup, do man nslookup, but on my system you do 'nslookup host server' so your first example would be

$response = `nslookup gunfreekids.org ns1.abs.net`;
[download]

it is usually goo to give the full path of your executable, though, such as /usr/bin/nslookup
                - Ant