I'm trying to use the  mcopy command (https://www.cgl.ucsf.edu/chimerax/docs/user/commands/mcopy.html) as such:

mcopy #1 toAtoms #2 settings a

However, I get the following error message:

Unknown command: mcopy #1 #2 settings a

Am I using the wrong syntax? I am using the latest chimerax release.

Thanks,