@James1138
I am including @Steve143 and @Charlotte302 here because this information may also be of use to you both.
You pose an interesting problem here James because Hong Kong is part of China but, this may be worth a try. If you use this link you can convert your bank account to an IBAN format in countries where the financial system uses IBAN!
http://www.creativeeyes.at/tools/iban.php
Now although this will convert your account to an IBAN format your bank may still reject it because some countries still do not use the IBAN format.
Here is a list of countries that use IBAN ......
https://www.xe.com/ibancalculator/countrylist/
Best to contact you bank and it is probable they will suggest you use a 'Swift' code instead of the IBAN which should be accepted! A Swift code is a 6 digit country, bank and branch identifier and finishes with your individual account number!
Cheers.....Rob