[otrs] Access to the tickets

Does anybody know if one can autoassign rights to customers ? I need to make all the queues to be RO by customers so that the tickets remain visible to them via customer.pl wherever tickets are. There's CustomerGroupAlwaysGroups which can assign users to groups, but it gives them not only RO but also RW rights to the group. I found group_customer_user table in OTRS DB I could add records to via script/triggers/etc.