Here is how I added syntax highlighting to a specific file type that is not listed by default in Dreamweaver.

First, I noted what language the template file is made up of. Even though the file extension is .phtml, I know that the actual language is php.

Second, I opened the document type config file in the Dreamweaver installation folder. This should be found in this general area.

C:\Program Files\Adobe\Dreamweaver CS3\Configuration\DocumentTypes\MMDocumentTypes.xml

I opened the file with Notepad, and hit Control + F, and entered winfileextension=”php as my search query. This jumped me down to where the list of file types that use a specific syntax highlighting. My list appeared as winfileextension=”php,php3,php4,php5″.

All I did was add a comma and phtml to the end of that list:

winfileextension=”php,php3,php4,php5,phtml”

Then I saved the file and restarted Dreamweaver. Now any file with the .phtml file extension receives the same syntax highlighting as a php document.

Before and After