Sample in.txt
BEGPUB Wirey Haired Dog's Life ENDPUB
BEGTITLE My dog has wirey hair ENDTITLE
BEGTXT My wirey hair dog...blah, blah. ENDTXT

##</code><code>##

#!/usr/bin/perl -w

open(INFILE,$ARGV[0]) or die "INFILE CROAKED";
open(OUTFILE,">$ARGV[1]) or die "OUTFILE CROAKED";

While(<INFILE>){
		while(/BEGTITLE.*wirey.*?ENDTITLE/){
		$_=~s/wirey/smooth/i;
		print OUTFILE $_;}
		}
close INFILE;
close OUTFILE;