As per the new release from Microsoft, Azure now supports custom culture.
Here are few links
Here is how you create a new culture and register it.
Remember, you might see some errors while registering the new culture, errors are related to "UnauthorizedAccessException". Please follow this article to find resolution:
As far as I know you cant really replicate the steps in the last link to solve the UnauthorizedAccessException in a web app.
If you have solved this could you please explain how and what steps you did?
Have there been any updates on this issue?