[AndersS]

If you have the free version, it's possible to copy the campaign scenarios (the .dat files) into the scenario map and then rename them to match the other scenario files, so that for instance C000S001.dat becomes spscn450.dat, or whatever you prefer. After that, you can edit them with the Scenario Editor. When you're done, simply reverse the process.

I've never experienced any trouble because of doing this, and don't believe it to be against any user agreements.