The only way you can do this is to have someone come in and feed them.
Obviously, you can't put a mass of frozen food in the tank, and you can't put it in an automatic fish feeder.
The best solution I have found is to just go away and leave everything alone. Feed normally the day you go and lightly on the day you return. I find this works out much better that having someone inexperienced with reef systems try to do anything. I've left my system alone for up to 2 weeks without any issues.
The one exception to this is if you have livestock that must be feed every day. This is usually fry (baby fish) or specialized feeders such as Anthias sp. damsels.