There are two answers to this. First, War bringer is correct, there's nothing about Dimensional Lock that implies one cannot teleport within the 1/2 mile radius you mentioned.
I'll disagree.
The first two sentences of the spell description state: "You create a shimmering emerald barrier that completely blocks extradimensional travel. Forms of movement barred include astral projection, blink, dimension door, ethereal jaunt, etherealness, gate, maze, plane shift, shadow walk, teleport, and similar spell-like or psionic abilities."
It doesn't matter where the far end of the transport spell is supposed to be, if the spell uses interdimensional travel, or even the possibility of it as an option (
Shadow walk), and either end is in the affected ares, the spell fails.
(Note that
Shadow Walk *can* be used to travel between dimensions, but its normal use only takes you to the edge of the Material plane where it borders with Shadow. It doesn't normally cross that line.)
And since it bars "similar spell-like or psionic abilities" I'd have to look long and hard at
Wish and
Limited Wish as well, if the end result is "similar" to any of the above spells.