Changing camera waypoints with collison

Hay,

I've been trying to make the following: Camera moves above player in pre-selected way. Player can't leave cameras sight. Player mainly just moves forward, BUT if player chooses other route (collides with thing), script changes cameras waypoints to be, also premade route, different ones. I've thought it to be something like:

if gameobject tagged player collides with ThisWayChangerCube { change waypoints a1 to b1 and a2 to b2 }

dunno why I even wrote that here, its just same thing I explained but in geekier way. Problem is I just don't know how to change those waypoints when two objects collide.. or actually I don't know how to change those waypoints with anything else than pulling those waypoint spheres to their places..

Code is not made by me, its same as this http://forum.unity3d.com/threads/54678-A-Waypoint-Script-Explained-in-Super-Detail! It just fits perfectly to my purpose, or so I'd like to think. Or is there easier/better way to solve this problem?