iCal subscribe to calendar unattended

[denose]

I'm wondering if anyone has done or has ideas on subscribing to a Public iCloud calendar, unattended. We have a lab running Mountain Lion and want to use Calendar/iCal to subscribe to 4 calendars. Using something like Composer to capture the changes and push fails, assumedly because it uses unique generated "ids" for each folder under the user's Library/Preferences/Calendar. Trying a script like "tell application iCal > GetURL https://calendar", does connect to the calendar but needs you to still Click Subscribe and confirm you settings. Hopefully that makes sense and someone knows a trick :)

[denose]

I believe I have this working now (only pushed to 2 machines so far but working on both). I did a Composer New & Modified snapshot, on a machine that's never opened Calendar.app before. Then make all the changes. I think where I went wrong originally is that I only captured adding the calendar subscriptions, not deleting the other default calendars.