How best to use Resist Damage powers

I've been having trouble finding a good way to utilize my players Resist damage powers. I like to have large battles and have not found an efficient way to put a resist power on a player's character, for example resist 10 damage for 1 round, or resist 5 encounter. I've only been able to create effects that I then have to apply to all of the monsters that are attacking the creature (not efficient). Also, if those creatures change targets they are still under the resist effect and thus apply that effect to their new target. I'd prefer not to have to modify the attack screen for every creature. If anybody has a better fix, please advise. And spell it out to me like a third grader how to utilize within d20pro. Thanks!