Eclipse: Treat a "dxml" file as a "xml" file?

So, I already downloaded 开发者_开发百科some plugin to syntax-highlight XML files. I work with these "DXML" files that are basically like XML files. Is there a way to get Eclipse to think a .dxml file is a .xml file?

Window->Preferences -> General -> Content Types. Select XML in the top half, then in the bottom half add *.dxml