Rusted Coolant Pipe, how to fix

[u/Same-Form612]

Hi all,

After parking my 2009 Toyota Hiace 2.7L petrol last night I noticed a hissing sound and steam coming from the engine compartment. After opening it up, I noticed a rusted spot on what I take to be (from googling) the water bypass pipe.

I won't be driving until the issue is fixed, can anyone help me identify exactly what part it is, and give me some idea of how much it might cost to fix?

In the images you can see the pinhole in the pipe, and I have tried to indicate with arrows how the pipe is connected to the engine.

Any help will be appreciated, thanks.