You can use ReportsZilla App it help building custom reports exactly what you need.
Hi @Simon_Westwood ,
Kritesh here from Better Reports support team.
I believe our app Better Reports may be able to help. We can track the number of orders and sales metrics by each country for any time period by day/week/month. We can also create a schedule this report to run at a regular cadence so that your monthly accounting needs can be automated.
If you need, we also have a "Is EU?" field that can segregate all sales metrics (gross, discounts, taxes, total sales, etc.) based on whether the Shipping or Billing country is part of EU.
I encourage you to install Better Reports and start your free 14-day trial, and I'll be happy to set this up for you.
Let me know how you go and feel free to reach out if you have any further questions.