I have a sheet which is a list of clients addresses, and I wish to categorise
each address as being inside or outside a geographical region that I have
defined.
I have a separate sheet with a list of streets within the region.

A typical address would be "11 Cumberland Road"
An entry in the list for the region would be "Cumberland"

What I want to do is write a function that returns True if any of the
entries in the region list appears within the client's address.