  << ^ N M - D E F I N E   M A C R O >>
 Sets the macro indicated by the character following ^NM (which must be there
if in a macro and must be a valid macro i.d.) to the current line being edited
or command being input. Works whether in command mode or editing a line. If
there is room for 2 extra chars, ^NU is added to the macro definition, so you
don't have to do it yourself.
 This pseudo-macro provides a feedback link from the data you are editing back
to your editing instructions. Typically you find a line with the data you want,
throw away the rest of the line, make the macro then ^[ (ESC) out of the line
so it goes back to its original state.
 Example: suppose you have 'found' an "FD" line in a COBOL program, and now you
want to remember the name of the file being defined (to put in the "VALUE OF
FILE-ID" perhaps). After the L-LOCATE, the cursor will be on the "F" of "FD".
 N A '^F^L^G ^K^NM^B^[^NU
 Call this macro by ^ND^N^A. How it works:
 Forward to the word we want                               ^F
 Throw away 1st part of line                               ^L
 Forward to 1st char we don't want or end of line          ^G<space>
 Throw away rest of line                                   ^K
 Define macro ^N^B as the name + ^NU  ** EXAMPLE **        ^NM^B
 ESCAPE to restore the line and exit                       ^[^NU
 If line had been "FD PRYNT LABEL ..."  ^N^B would now be "PRYNT^NU".
