I made a very detailed script that allows for some really interesting control of that kind of thing and allows for easily adding a wide variety of types of commands and responses. However, it's not entirely ready for public use so I can't give it out at this time.
However, for a very basic setup, that is easy to edit, just do this:
on *:text:!*:#yourchannel: {
if ($readini(mycommands.ini,$1)) {
describe $chan $replace($readini(mycommands.ini,n,$1,$rand(1,$ini(mycommands.ini,$1,0))),#2#,$2)
}
}
Then, create a file called mycommands.ini and format it like this:
[!taco]
1=launches a delicious taco toward #2#
2=gives #2# a delicious taco
[!othercommand]
1=something
2=something else
#2# in the ini refers to word #2. In your example, that is the person's nick. If you need additional words, the $replace() can be updated to change #3# to $3, etc.
This isn't as configurable as is possible, but it's quickly set up and easy to change.
Replace #yourchannel with your channel name. And if you need commands that don't start with !, then remove that from the on text event and just use * instead of !*.