I don't believe you can do what you have in mind - you can use military addresses to send to someone however, PayPal accounts are based on the country one lives in. You may want to follow-up with customer support as they may have a better answer or work around.
Hi , I was having the same problem before but what i did is I signed up using my inlaws address in the US and when I log in to my account i add new address and it let me to put our APO address ( the option for the AP is in the bottom). and it also allows you to put it as your primary address and delete the one you use to sign up. 🙂
