1) Attack macros like this aren't possible.
2) You can find a how-to on attack/defence attributes here.
The short answer is, they work like a modifier, e.g. a value of 100 would do 100 % damage, 150 does 150 % damage, etc.
Negative values will turn damage to regeneration, e.g. -50 regenerates 50 %.
Attack attributes are assigned to attacks and use the target's value, e.g. a fire attack uses the target's fire attribute for calculation.
Defence attributes are assigned to combatants and use the attacker's value, e.g. attacking an insect uses the attacker's insect attribute.