The only way a new page can get that information is if the previous page passes it through GET or POST. This would be through a form, or even hard coded into the URL. Your best option is to pass it through the URL.

Code:
http://www.domain.com/page.php?list=one,two,three
Alternatively, you could use the PHP page to read the contents of the other and then parse the data. That would be a little bit more code. And, mostly likely a waste of time.