Hi dude,
What you are after is enabling and disabling the collider.
You can try using the set and get property actions in playmaker if you can't find any that works for you.
Simply drag and drop the box collider into the variable slot in the playmaker action and your good to go. All you would have to do then is to turn it back on when you reach your destination.
You might have the problem though of the gameobject falling through the floor if it has a rigid body. If thats the case, try turning on is kinematic in the rigidbody component and leaving the collider part alone. Then turning is kinematic off when you get to your destination. There is a playmaker action you can use to toggle its on/off state.
If you get stuck, let me know and I will try and help you out. Just let me know your setup.