You're correct -- you cannot do a right-click in a Help topic to copy text. Instead, simply select the text to copy and press CTRL+C to copy. You can then use CTRL + V to paste the selected text into any file or search.
Since AutoCAD and AutoCAD Electrical are part of two different divisions of Autodesk, we do not use the same tools to create our Help systems. You will notice slight differences between the two for this reason (such as how to copy, the overall look of the Help, etc.).
Thanks,
Heather Schwartz
Autodesk/AutoCAD Electrical DSS