A script to trasfer webpage content from another site.

I need a script to extract page content from another site to a page on my site. For example my web page is here [login to view URL], their page is here [login to view URL] When a user come to my site and access [login to view URL] [login to view URL] the content is dynamically extracted from [login to view URL] and put it in mypage.html. I have permission to use their web content material, so copyright is no problem. I do not have access to [login to view URL] but I know where the pages are. The [login to view URL] uses [login to view URL], XML/php/dtd and things like that. If you know how to do this send me a message. I will give you more details about the sites.