I read a lot of forum posts on the "CHSPACE" command in regards to AutoCAD LT for Mac and finally reached out and called a technician who looked into it. I had even found an erroneous help page which showed that CHSPACE was available to Mac Users - unfortunately, it isn't ... yet. Below is the response from the Autodesk Technician - she was very helpful!
"I was able to confirm with our technicians that the CHSPACE command written in Lisp (as part of AutoCAD Express Tools) is not yet available on Mac regardless of the version or being full or LT AutoCAD. They also let me know that adding this function for Mac is currently in the works for the near future."
August 7, 2014.