#!/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";