Calendars

I have php Icalendar on my server and I need it configuring and instructions set so that I can publish using Sunbird or iCal equivilant. When viewing the calendars I would like it so that I have to pass a variable to iCalendar such as ?cal=tweba and then php iCalendar opens the [login to view URL] icalendar file within a given folder. The file will then need to synchronise with the subnird application as mentioned above. Basically i am trying to create a place where given users can publich their calendar but where other users (viaa link) can view the calendar online. ps I do not have webdav which is why phpicalendar is vital. If there is another open source product you would prefer please let me know. Many thanks Ashley