I have a named_scope in rails that finds episodes by there directors given name

  named_scope :director_given, lambda { |dr| {:joins => :director, :conditions => ['given = ?', dr]} }

It works great but I would like it to also work on substrings one the name. e.g. instead of having to search for 'Lucy' you could just search 'Lu'.

P.S. I also have another named scope which does exactly the same thing but on the directors last name. It there a way to combine the two?

Thanks,