I made a risk control point system as a spell recently
Its not approved, but it could help you (meaning its in the "Pending Spells" section, sub-sect from spells)
Risk Map Control Points System
I suggest you learn more about triggers, so you don't need to ask, just get it done the way you want
*Please Note
The system I made is for risk-mappers who don't want to do all that endless clicking (GUI-ers of course)
It may be a bit overkill for your map, but it will definitely fit your purpose
If you would like to mess with the system you can, but until you know EXACTLY what your doing, just copy the triggs and edit the copies (I would also disable them until your finished, then enable when you test them, vice-versa for the original triggs your not messing with)