Add extra time to the delivery time given by AliExpress

Hello
I have a business model where the product purchased by a customer in my online store is shipped from China to the United States to a PO box. Another shipping company then ships the product to my country, taking between 2 and 5 days. I’d like to find a way to add the 2 to 5 days it takes the product to arrive in my country from the USA to the delivery time shown by the plugin and obtained from Aliexpress. I’d like to display this total delivery time on the product page and at checkout.