William,

OK.  The batch comand I submitted earlier 

  httrack --update -O "X:\Mirrors\bob.com,X:\Cache\bob.com"

seems to work except it adds, each time I run it, a new instance of the
following to the doit.log...

  -iC2 -O "X:\\Mirors\\bob.com,X:\\Cache\\bob.com"

So, if I've run the update four times, I have the preceeding line in the
doit.log four times.

This doesn't appear to hurt anything, but it's just a bit odd.

Cheers!

-- Cliff