proxy authentication (NTLM)

[sleeper.design]

i have a problem connecting through a corporate proxy (squid) that is configured to use NTLM authentication.

i tried:
export http_proxy = http://local.proxy.address:8080
export http_proxy_username = domain\username
export http_proxy_password = password

and also

export http_proxy = http://domain\username:password@local.proxy.address:8080
but it doesn't work.

any ideas?