Use the Tcl command remove_from_collection to remove those specific nets from the original get_nets collection.
Don't know if there is another way to do it as I haven't used DC in decades, but other tools (Altera/xilinx) have the same command and a quick check showed that DC has this same command.
Another option for you is to use -filter option, and you can combine with "full_name != "victim": get_nets * -filter "full_name != victim". Please check the syntax on DC man page.
Be careful if you are handling a flattern design which may content hierarchy character in net name.