How to use: Save that thingy as an XML file or paste it into a new XML file. Open Notepad++. Go to View > User Defined Dialog... and click the Import button. Open that thing. Whenever you open a .pop file it should use that syntax highlighter. If it doesn't, click Language on the menu bar and you should see "mvm_popfile" as an option. Click it, bro.
If you've got any suggestions, comments, or missing keywords, lemme know. I'll try and add what I missed.