Can you access it via a webserver? That'd be the easy way.
[man]fopen[/man] a connection to the PHP script via HTTP, and [man]fread[/man] the data into a variable.
Another way would be to use [man]ob_start[/man] on the PHP script you're trying to read the HTML off, use [man]ob_get_contents[/man] to store the buffer in a vaiable, and then [man]return[/man] the variable in the script, NOT echo/print. Then, look at the [man]include[/man] page on how to store the returned data of a script to a variable (Example 16-10).