apt-get build cd

i think theres a how to some where but dam if i can find it . this is what i am trying to do , i want to down load rpms to a cd and use it as a apt-get repositorie so i can 1 have a copy and 2 install them when i want to so it would go apt-get cd rom bla bla  but thats what i am triing to do . is it posible and is there a how to on this ?