Need some more help with my custom story!

[Zaapeer]

Okay, so I've come to a part in my custom story where the player is supposed to cross like a big hole in the ground. In order to do so he needs to but a plank over it to be able to walk over. Now here's my problem: How do you make it so that when the plank touches a special area it automatically changes into a static object and places itself over the hole? I appreciate all the help I can can get, thanks!