You need to figure out what is actually wrong.

"Leaking" how?

What is the exterior?

Water seeps out of the bricks where the supply pipe would be. It's brick exterior.

Before you tear into paneling, make sure the water is from a leaky pipe and not some other source (like a roof leak). Do you have a continuous, uniform seepage flow? Have you checked to see if your water meter is turning when all the taps in the house are turned off?

If you need to get at the supply line go through the brick side of the home. Your paneling will be very difficult to remove and replace. A good brick man can replace the bricks and match the mortar.

Going through the brick wall (especially if it is brick veneer only one brick thick) is liable to be far less destructive than cutting into you paneling.

Removing a few bricks look hard but is actually not that bad.

A few holes drilled around the bricks in the mortar, then clearing with a plugging chisel, should free the bricks without damaging them.

You may need to find a local mason who can match the mortar to put everything back together.

Local sand has a lot to do with what color the mortar is in many cases.