This would be a complete kiwiirc URL:
http://example.com/kiwi/irc.server.com:+6697?nick=prawnsalad&encoding=ascii&theme=relaxed#channelNot all parts are required, but a few notes:
1. The /kiwi/ part of the URL depends on your config.js. Default is /kiwi/
2. If you have the restrict_server* config options set in config.js, the server address is ignored.
3. The channel must be last, as anything after # is read differently in the browser.
If you do specifically need POST instead of this format of URL, you can generate a PHP script that reads the POST vars and generates the kiwi URL, redirecting the browser to it.
Darren