I've attempted to follow the instructions for the form based authentication,
but I've noticed that my proxy's address isn't in the standard format. Here's
what I get for a proxy address:

fe80::614e:756a:d4b:38c%18  (I've altered the numbers a bit in case it's
sensitive info)

HTTrack wasn't able to capture the link. I'm assuming it's because of the
address.

Any ideas?