OK, thanks, I try many different combinations but I always use firstname.lastname@example.org that was incorrect I should use only user=username
For those who want to use iCal with shared calendars:
user1 - Your user name (person who add shared calendar)
password - Your password
mail.domain.com - domain name plus path to your company calendars
user2 - person who create shared calendar
calendar_name.ics - calendar name
For me second problem was to add https path to iCal...
If You want to do that, you must prepare a file on your mac.
next You open iCal -> Subscribe and you add
~/Sites/somefile.php (with this inside)
<?php readfile("https://user1:email@example.com/service/home/user2/calendar_name.ics"); ?>
this should works
once more, if you want use https with this php file you should start web server (on your mac) and you should install php (if you don't know how to, easiest way is to download this package and install)