Try changing the include to "../CMS" or just "CMS" for your include.
What i meant was that when you purchase the HTMLEditor, you can just add the HTMLEditor to other pages and it will automatically adjust the path accordingly. So if you wanted to add the HTMLEditor to myfile.php, then you just open the file in DW (in a site) and then choose Insert -> WebAssist > HTMLEditor -> Insert Editor, and then you choose the type of editor (with or with out upload) and then type the name of the editor and click OK, and the HTMLEditor will be added to your page.