It is not possible. iTunes, as well as most other podcatchers and podcasting directories will either pickup the first or last media file associated to one blog post. See first item in the FAQ, which explains the problem as well as why this comes up again and again as a problem: http://wordpress.org/extend/plugins/powerpress/faq/
You also originally used the language "page". Keep in mind that any media you add to a "page" (not a "post") will never be syndicated (placed into a feed). If it's not in a feed, it will not be picked up by iTunes.
If you are trying to use the same post content and post title for say 3 media files, keep in mind that iTunes may filter out duplicate post titles (depending how they have iTunes app configured). I know this adds more work for you, but I would recommend using the "Duplicate Posts" plugin to copy your last blog post as a solution. Before you "publish" the newly copied post, go in to edit it and change the title slightly. For readability in iTunes, I recommend prefixing the blog post title with an episode number, this is useful not only for the listener to know which episode the podcast is, but also because the iTunes app for that listener may be configured to rename the mp3 file to the title of the blog post (the reason you do not want to reuse the same blog post title for multiple episodes).