Hehe. That's quite a monster. I'll try to be a bit more helpful.

1. Use loop instead of dotimes so you can make the index range over 1-100 instead of 0-99.

2. Factor out the string calculation so you only need one print statement.

3. Maybe use zerop.

4. Don't write ")(". Use a space in between.

Example:

    (loop for n from 1 to 100
          do (format t "~a~%"
                     (cond
                      ((and (zerop (mod n 3))
                            (zerop (mod n 5)))
                       "FizzBuzz")
                      ((zerop (mod n 3)) "Fizz")
                      ((zerop (mod n 5)) "Buzz")
                      (t (format nil "~a" n)))))