It would be extremely helpful to be able to copy text directly from the MGED Command window using the standard copy (Cntl-C).
Paste (Cntl-V) currently works.
As a workaround to not having Cntl-C, one can use the Combination Editor's Boolean Expression TextBox, since it allows the use of Cntl-C:
Open the 'Combination Editor', select text in the CMD window, and center click in the Combination Editor's Boolean Expression TextBox. This puts the selected text in to this TextBox which can then be Cntl-C'ed out.