Directory browsing a URL... opendir( ) ?

I have a script that runs on a PHP enabled IIS server called server1.
I want to be able to determine the contents of a secondary server,
server2 also running IIS via a URL. The functionality I require is
that of opendir() to establish what files and folders are located at
the URL pointing at server2. However, I've not managed to get this
syntax working. I have verified that directory browsing for the
directory in question on server2 is operational.

Thanks in advance for any help.