/usr/bin/perl -w
use strict;
use warnings;
use re 'eval';
use Regexp::Common;

my $text= "start \\chapter{argument1}{argument2} end";
print "INPUT: $text\n";

################################################################
my $arg1= qr/\s*($RE{balanced}{-parens=>'{ }'})/;
my $args2= $arg1.$arg1;

my $macronamereadfromfile="chapter";
my $patternreadfromfile= "<h1 tag=\"\$2\">\$1</h1>";

my $inpattern = "\\\\$macronamereadfromfile$args2";

my $outpattern = qq{ qq{$patternreadfromfile} };

#print "PATTERNS: '$inpattern'.  to='$patternreadfromfile'.  became='$outpattern'\n";

$text =~ s/$inpattern/$outpattern/gee;

################################################################

print "OUTPUT: '$text'\n\n";

##</code><code>##

OUTPUT: 'start <h1 tag="argument1">argument1</h1> end'

##</code><code>##

OUTPUT: 'start <h1 tag="{argument1}">{argument1}</h1> end'