Well, there are other ways around, like slowly breaking enough stone to create a tunnel.
Some ideas:

1) Righteous Might ( increased weapon size and +4 size Strenght ) + Divine Power ( +6 enachement Strenght and higher BAB )
It doesn't last much ( 8-7 rounds ) but it should allow to break the hardest blocks of stone

2) Magic Weapon, Greater
It lasts many hours and provides an excavating tool sturdy enough to break stone quite easily

3) Bull's Strenght
Lasts many hours and Redcloak can cast many of them. Could be useful to help the other goblins digging that tunnel.

4) Stone Shape
That looks very useful, if the stone itself isn't warded against direct magic