You can right-click on the uhp file and select the OPEN WITH section
to select any character editor of your choice like notepad, wordpad, etc.
Jerry recommended a nice FREE editor called Crimson Editor which I now also use.
Make your changes and resave it with a uhp extension.
If it does not, then rename the extension from .txt to .uhp and all should be fine.
Be careful with using noteped with cut/copy/paste functions as sometimes a stray space might cause problems.
Keep us posted.