Certified GKH Gardening Expert
Moss doesn't operate like your, typical, plant. Instead of controlling what is there, it will be necessary to control the environment of the area to prevent moss. This will mean allowing the area to dry out, removing obstruction to sun, and increasing airflow.
If this cannot be arranged, then harsh and constant chemical control may be necessary. Keep in mind that if this becomes the case, then it would have much less effect on the environment to leave it in its natural state.