You may already faced this issue, when you run your rebol.exe directly or from a shortcut your user.r file will be loaded and you'll be able to use your favorite functions like cls or something in your user.r file.
But it won't be loaded if you execute your script from inside a text editor (like Editplus). So when you halt the execution you won't be able to use those functions in your user.r file.
Here is the solution I've found:
-i --secure allow --do "do join first split-path system/options/boot %user.r" --script "$(FilePath)"
-i is for "no install" for view & link only.
Note that the --do "..." part. You can change it to any file you want to be loaded when you execute a file.
This is for Editplus but will mostly be same for other text editors.