open(HTML,"<$html_file") || die "Could not open $html_file:$!\n";
open(TXT,"<$txt_file") || die "Could not open $txt_file:$!\n";
open(OUT,">$output_file) || die "Could not open $ouput_file:$!\n";
while () {
print OUT $_;
if (/this is how you recognise the specific point/) {
while () {
print OUT $_;
}
}
}