Nick here from Shopify! ?
Great question, as this cannot be done directly from within the Shopify platform and is not easy to find. I looked around for you to find a solution and did find something:
Hope this helps and don't hesitate should you have any other questions about anything else.
All the best,
Another solution that is actually free is Profitario.
Their website is here: https://www.profitario.com/aliexpress
A HowTo video explaining you how to set everything up is here:
Cheers, I hope this helped.