Well this is one way.
First put this script in your hps. Put it in Void OnEnter for example.
void OnEnter()
{
AddEntityCollideCallback("ENTITYNAME", "AREANAME", "SCRIPT", false, 1);
}
Make an script area over to your "hole". And the board you want to be as a bridge. Make that board non active and check the "StaticPhysics" box.
Next we need the script to continue like this.
void SCRIPT(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("ENTITYNAME", false);
SetEntityActive("your_static_board", true);
}
Now thats simply it. So here is the whole script spiced with a little puzzlemusic and sanity gain. You can of course leave them out of your script if you wan't.
Hopefully I was any help for you.
void OnEnter()
{
AddEntityCollideCallback("ENTITYNAME", "AREANAME", "SCRIPT", false, 1);
}
void SCRIPT(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("ENTITYNAME", false);
SetEntityActive("your_static_board", true);
PlayMusic("12_puzzle_cavein.ogg", false, 1.0, 0, 1, true);
GiveSanityBoost();
}