Ok, so we can use environment variables to restart a batch file at a given
point as we just saw.  However, we can also make use of the "magic"
properties of the "%0" parameter, the "name" of the invoking batch file!

Recall that %0 holds the entire command line up to the first blank, but
great mother DOS only reads either 8 characters or up to a "." when it
looks for a file name. Thus if we type:

        DEMO_1.andmorejunk parm1

        DEMO_1.BAT gets called  (DOS only reads up to the "." remember)

                               but!

        %0  == DEMO_1.andmorejunk        %1  == parm1

Lets see how this lets us restart at any point desired, without any need
for the environment, nor any change to any %1 %2 %3 parms we use either.

Take a good look at the batch file code for DEMO_1.BAT right now, using
Vern Buerg's LIST (L.COM) program.