Additional Targeting within Pre-Built SQL

I have a pre-built SQL which is used to automatically target customers within a set transactional range with a certain marketing message (let's call this A), it looks at a customer's transactions in X time-period.

The current pre-built SQL excludes variables such as specific countries, different types of accounts etc.

I am looking to use this SQL to show an additional marketing message (let's call this B) to customers in certain countries.

So customer 1 who is within X% of <$ TARGET> and is NOT in country X sees marketing messages A & B. However customer 2, who is within the same % of and DOES live in country Y only sees marketing message A.

Does anyone know how to go about adding this in to the current pre-built SQL?

Is this real world situation? Or is this job interview or homework?

real world

i think views will help

or you can write SQL
with case when

just initial thoughts

Please provide your thoughts

Can you share your data structure as it is now?
we need sample tables and sample data like the following

create table #customers(customerid int not null , 
customername varchar(50),countryofResidence varchar(30) )
create table #customerTransactions(customerid int not null, 
transactiondate datetime, transactionAmount money)
create table #marketingMessage(messageid int not null, 
marketingMessage varchar(250), isExpired bit default((0)) )
create table #targets(targetAmount decimal(4,1), targetYear int)

insert into #targets
select 1.5, 2018 union
select 50, 2019 

insert into #customers
select 1, 'Customer 1', 'Tatooine' union
select 2, 'Customer 2' , 'Naboo'

insert into #customerTransactions
select distinct 1, DATEADD(mm,column_id, getdate()), column_id * 0.99
  from sys.columns
  where column_id between 1 and 9
select distinct 2, DATEADD(mm,column_id, getdate()), column_id * 0.99
  from sys.columns
  where column_id between 1 and 7

insert into #marketingMessage
select 1, '50% off with purchase of hoverboard!', 1 union
select 2, '20% off with purchase of toothbrush!', 1 union
select 3, 'Buy 1 get 3 free kittens!', 1

;with cte
select c.customername, 
       sum(ct.transactionAmount) Amount, 
  From #customers c
   join #customerTransactions ct on c.customerid = ct.customerid
   join #targets t on t.targetYear = year(ct.transactiondate)   
group by c.customername, t.targetYear
select * , 
	      when ( (100 - (Amount/t.targetAmount) * 100) between 12 and 13 )  then 'HA'
		  else 'HO'
	   end as marketingMessage
  From cte 
  join #targets t on cte.targetYear = t.targetYear

drop table #customerTransactions
drop table #customers
drop table #marketingMessage
drop table #targets