At the moment you can't cop/cut/paste RealDrum sections like you can RealTracks.
You can load the original RealDrum source file into a Utility track and set it's tempo if different to the project tempo, you can then cut/copy/paste sections, but it will be an attached wav file.
Once non destructive editing is added all this will be just so easy to get what you want:

Attached Files (Click to download or enlarge) (Only available when you are logged in)
BB23-Drums-Copy-Audio-Edit.gif (214.91 KB, 129 downloads)
BB23-NDE-Audio-Edit.gif (421.95 KB, 129 downloads)