$line =~ s/\n/ /g;

I don't understand this statement in poj's code: why are all newlines being changed to spaces?

$line =~ s/ (\d+\. )/\n$1/g;

This statement seems to speak to a requirement to add newlines before every  1.  23.  345. pattern, but I can't see where this has ever been discussed before. Please give more info on this.

It would help if you could post a short example of an input file and a corresponding file representing the exact output you want from it. By short, I mean that most of the data in the input file you have already posted seems redundant; please try to keep example data short and sweet.

And once again, the statement that the result of a piece of code is "no good" is not helpful; in what way is it no good? You should say "With this code and this input data, I want to get 'XXX' and I am getting 'YYY'."

Your addition should have worked but anyway try this

#!perl
# Aufruf: perl removeEK1.pl TestEK.txt > Out.txt
use strict;
use warnings;
my $regex = '{\[%tqu[^\]]*]}';
my $line = do { local $/;  <>; }; 
$line =~ s/\n/ /g;
$line =~ s/$regex//gi;
$line =~ s/ (\d+\. |\[)/\n$1/g;
print $line;
[download]

Thank you poj for helping me again, now it works like a charm. I have tried to solve the remaining problem by myself like this:

#!/usr/bin/perl 
# Remove extra text from a PGN or Text-file.
use strict;
use warnings;
my $regex = '{\[%tqu[^\]]*]}';
my $line = do { local $/;  <>; }; 
$line =~ s/\n/ /g;            
$line =~ s/$regex//gi;
# these statements I have inserted
$line =~ s/\]/\]\n/g; 
$line =~ s/\[E/\n\[E/g; 
#  end
$line =~ s/ (\d+\. )/\n$1/g;
print $line;
[download]

and it "nearly" worked, but I got an empty first line in the outputfile.