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Hi Aaron,

You can edit command aliases in 2013 version, but you have to use Textedit application (or some other plain text editor) for this.
You can use menu Tools -> Customize -> Edit Command Aliases (PGP) to open acad.pgp in Textedit app and edit acad.pgp in it. If you edit the PGP file while the program is running, enter RE-INIT and then a value of 16 to use the revised file.

See here:
http://docs.autodesk.com/ACDMAC/2013/ENU/filesACRMac/GUID-D654A057-799D-4B03-878E-882B7A81E6F2.htm?h...

http://docs.autodesk.com/ACDMAC/2013/ENU/filesACGMac/GUID-A37DAD86-971E-4E5E-8D9A-DF03DC315336.htm?h...