pkg_add -r through Proxy/Firewall?

[a at jenisch.at]

Hi,

Sitting behind a firewall that doesn't allow direkt ftp (neither
active nor passive) I'm looking for a way to fetch packages
(i.e. "pkg_add -r") from the Internet. What's possible though is doing
http or ftp through a proxy server.

So, how do I instruct pkg_add to download packages either via ftp or
http through a proxy?

Thanks much in advance for your help,
-ewald