corners problem

[rammie2011]

hopefully someone can help, ive got a mint formation an win loads but wana do sumat from attacking corner kicks to enhance my game. ive got the idea to aim all corners near post with a player attacking near post. thats all cool, can do that, then have left 2 players back which leaves me with 6 outfield players. these 6 i want to be lurking outside box, but can only get 1 player to do that role, when i try to add others to lurk outside box, it only offers me the opportunity to swap roles. basically, i want 6 players to lurk outside box, but have only been able to get 1 player on that role only, can sum1 please tell me how i can get all 6 to be lurking outside box please.