Print value in column conditional on matching values against another list

I a have a list of newsletter recipent addresses. The list contains street address, city, state, zipcode. I want to mail each of those users a letter including information about a store that is geographically nearest to them. I have another list that contains store information for my company, including storecode, address, city, state and zipcode.

So in this example I have two worksheets: 1) user address list 2) list of stores
I want to match on zipcode (or city name) the values between the two lists and print a storecode value per user record. If the zipcode (or city) from the user list does not match a record in the store list, then print "not found".

Here is an example. First we start with the user list:

street address	city	state	zipcode
123 main st	austin	tx	78701
456 BFE blvd	anchorage	ak	99501
789 rodeo dr	beverly hills	ca	90210

Here is an example store list:

storecode	address	city	state	zipcode
ATXSTORE	123 Congress Ave	austin	tx	78701
LASTORE	456 Stars blvd	beverly hills	ca	91210

I'm asking that someone provide guidance on a method that given the above two inputs, would yield the following result:

combined RESULT (augmented user list table):

user address	city	state	zipcode	nearest STORE
123 main st	austin	tx	78701	ATXSTORE
456 BFE blvd	anchorage	ak	99501	not found
789 rodeo dr	beverly hills	ca	90210	LASTORE

any help is greatly appreciated!