Use a dynamic variable like
set $+(%,hpp1,.,<nick>) 99
And to increase it, use inc $+(%,hpp1,.,<nick>)
To decrease, use dec $+(%,hpp1,.,<nick>)
Replace <nick> in each of the above examples with the variable or identifier that is being used and contains the person's nick.
You could also replace it with a variable that contains the person's IP address, however, obtaining that address can be more difficult