Search Kissassist1004e15.mac which comes with the redguides updater for mq2damageparser for examples of how it works.
Basically ${Damage.Total[mobid]} gives you total damage done to that mob.
${Damage.Individual[mobid,playerid]} gives you damage for that player on that mob.
Playerid is optional if you just do ${Damage.Individual[mobid]} it will use your players id.
That's basically it for now, I have plans to be able to get more info out like ${Damage.Individual[mobid,playerid].1HS} to return 1 hand slash damage for example.
You can count on this parser to be as close to the truth as it gets cause it doesn't rely on reading the log, it saves damage directly from the correct eqgame function that handles hits.
Also I would be interested in hearing from someone who uses it if it actually parses dots as well cause I'm not 100% sure about that.