If it's like Flash Live Media Encoder, the address would look something like what's on this page;

http://www.livestream.com/userguide/inde...Livestream

So it'd look something like
"rtmp://publish.livestream.com/mogulus/ncfc2011/username=yourusername
/password=yourpassword/isAutoLive=true"

Also, maybe this FFMPEG guide might be helpful:
http://ffmpeg.org/trac/ffmpeg/wiki/StreamingGuide