You managed to find an old post from 2007 and since that many people have tested different kinds of TinyMCE integrations, lib based, theme based and core editor of moodle 2 is already tinymce.
As an administrator you could try to upload those templates anywhere (with absolute urls) and use those urls in template init code or for example load the files to site files (course id 1 = front page) but if you want to use course files directly in template plugin you may need to rewrite the whole plugin. Most old integrations use file_browser_callback together with modified image and link plugins that use different courcefiles.php file to handle course files (a hack to files/index.php) but I have not heard that somebody had tried to use template plugin with course files.
Note also that this old hack was based on an old version of tinymce that should have been removed from moodle 1.X many years ago
this.majorVersion = "2";
this.minorVersion = "0.3";
this.releaseDate = "2006-02-13";
Latest version of TinyMCE is already 3.4b3 and downloadable from http://tinymce.moxiecode.com/