You should check if PAR cannot help you getting the lwp-download (installed with the LWP distribuition) with a package and deploy it to the AIX. But probably your limited access to the AIX box won't let you do it.

The Advanced Perl Programming book probably has a example or two using Sockets and IO::Sockets modules that you may use. You can try the Safary to have access to it. But you need to cross your fingers, because AIX is not particular updated when the subject is Perl and it's modules.

Maybe downloading what you need in another box and having access to the file thru NFS is a better solution for you, after all.