Roundcube CALENDAR and LIVE! URL subscriptions to .ics APIs

[Roundy13]

I am trying to add:
http://www.stanza.co/api/schedules/southerncalifornia/composite.ics?
to my calendar so that I can get a live update on coming events in my area.
I have a sub= & tamp= which will provide my credentials.
This is a live! URL version of "ics" and not a file so it does not upload correctly.
How can I add it to my calendar? Anyone have any ideas?