Either get permission to get through the firewall or figure out how to proxy your ppm session -- I believe there exists a way to do it. Installing modules by hand is very 1989... Avoid doing it at all costs. It would make more sense to drive your dev computer to an internet cafe than install the modules by hand. I'm exaggerating...

But if you really must, you can just download all the prereqs listed in the Makefile.PL, then download allt he prereqs from those, and so on and build them all by hand. But you will run into trouble. The PPMs have solved all the hard problems for you, so they're worth using.