Garymum4d,
Check out http://phpicalendar.sourceforge.net/nuke/index.php
phpicalendar is a web/php based calendar program that reads .ics files generated by ical. You will have to activate php on your web server if it isn't already. If you don't know how to activate php, check out Marc...
It sounds like your router on the client side is still not allowing communications over the ARD port or you are not connecting the correct way. You shouldn't have to port map ARD access on the admin side of things. I would revisit the router and make sure you have the ARD ports routed to your...
Matsaki,
Apple Remote Desktop uses UDP port 3283 for communications. If your office machine is behind a firewall, make sure all outside requests for port 3283 are being forwarded to it.
Apple has a nice list of used ports:
http://docs.info.apple.com/article.html?artnum=106439
Also...