Thanks for the sepcification, makes life easier
The reference to macro's have nothing to do with grep/sed (as stated on page 70, bottom paragraph). The macro file they are talking about (/usr/lib/macros/mmt) comes with troff (page 71, top) and is used in the getmac script.
These (troff) macro files migth not be installed on your box.
Hope this clears things up a bit.