Setting attributes on a has_many through relationship

The has_many through setup detailed below allows me to do @system.software << and @software.systems << for establishing the relationships, using an array of software or system objects, respectively. This works out well because my form for software has a software_ids multi-select. The problem I have is that the join model has additional attributes to store. Can I use the above method and somehow also include the additional attributes or do I have to do x = SystemSoftware.new... x.system_status = SystemStatus.find(params [:system_status_id]...etc.?

System.rb

has_many :system_software has_many :software, :through => :system_software

Software.rb

has_many :system_software has_many :software, :through => :system_software

SystemSoftware.rb

belongs_to :system belongs_to :software