Question about creating a certificate for SOLiD

I'm trying to use PHP to create a certificate for SOLiD.  It is not immediately clear to me how to set things other than distinguished name. I'm after "subject alternative name" etc. I see it here with openssl (http://blog.endpoint.com/2014/10/openssl-csr-with-alternative-names-one.html) but not with php
( http://php.net/manual/en/ref.openssl.php ). The functionality may not built into php. I may need to use the exec or shell_exec php function.

Also see: http://stackoverflow.com/questions/29861501/using-exec-with-php-to-run-a-command