This command is used to copy a portion of a polyline, at specified
points, and put the copied portion onto another layer. The portion of
existing polyline that is being copied still remains as part of the
original entity (with no break) , while the new portion, with its
chosen layer designation, is a new polyline.
Pulldown Menu Location: Edit > Copy
Keyboard Command: copy_pl
Prerequisite: Polyline to be copied