I have a .bat program that searches a log file for line that has some
unique data (we will call XXX). Once I have the XXX, I continue the
search down the file looking for other lines now containing XXX,
extracting out other pieces of data from those additional lines I want.

The program that creates the log file that I am searching has now been
changed in the way it writes out the data. The line with XXX is now
below the other lines I need.

Does a program/method exist that can be use in my batch file that allows
for a reverse search of a file based on a starting point? In my case
the starting point would be the line number containing XXX.