Applying an arbitrary template to a post

Here’s what I want to do. On the main page of my site, each post will have a link to open up that post in a new window. In this new window, what I will basically show is the title of the post and an audio player. If it matters, this is for a podcast. I want people to be able to open up a new window where they can play the audio and they can continue browsing in their main window.

Thus far, the best I can do is to edit the “single.php” file to look like how I want it to. This is almost good, but it’s not quite what I want because I want the single.php functionality to remain how it is. Ideally, I would like to create a new template file and call it “external-player.php” and force the post loaded into the new window to use this new template.

It doesn’t seem that wordpress will allow you to use a template in this way. Am I missing something?