The only other way is to use a parser which reads in your combined config and splits it out into http/https blocks.
ea. http://stackoverflow.com/questions/15277453/any-good-way-to-programmatically-change-nginx-config-file-from-python
ea. http://stackoverflow.com/questions/15277453/any-good-way-to-programmatically-change-nginx-config-file-from-python