Threat system request

Level 2
Jan 16, 2006
Is there any way to be able to make a threat system?
Usually warcraft 3 creeps attack the first unit that they see, but with a threat system, they would attack the one doing most damage to them.

(If you played World of Warcraft you will know what I speak of)

Say I do 100 damage to a creep, and it attacks me, then my friend comes along and hit it for 150, the creep whould now attack my friend. Is this possible?

Thank you in advice