I have a question regarding delaying interpolation of a variable when it is used in a regular expression. The below code snippet demonstrates the problem

%cat test.pl

#!/usr/bin/perl
use strict;
my $line  = "System has tool zigzag version 3.6";

my $match = 'System\s+has\s+tool\s+([0-9a-zA-Z_-]+)\s+version\s+(.*)';
my $replace = 'System has tool $1 version ABC';

$line =~ s/$match/$replace/g;
print "Line after replacement: $line \n";
[download]

%./test.pl

Line after replacement: System has tool $1 version ABC

The output I need is :

Line after replacement: System has tool zigzag version ABC

How do I get $1 to be interpolated in the replacement pattern ? I tried other variants like : e,ee etc but none yeild the result I need.