OpenVPN port-share has nothing to do with which HTTP server is running behind it. You should have a completely working Apache configuration separate from anything connected to OpenVPN, then you can change the listening port for HTTPD and have OpenVPN forward traffic to it.
The sites-enabled folder is part of the way some distributions (I think mainly Debian-based) like to set up HTTPD, but there is nothing special about it. If you install the Debian/Ubuntu/etc. package on the same OS, you will probably have /etc/apache2/sites-enabled/default also.
Either way, unless you have absolutely no other choice, don't do this. It slows down your OpenVPN and HTTPS traffic and it does not provide any additional security benefits.
- Y
