#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11151867
use warnings;

open my $fh, '<', 'config.file' or die;
my $configlist = join '', <$fh>;
close $fh;

open $fh, '<', 'gamelist.txt' or die;
while( <$fh> )
  {
  chomp;
  (my $newfile = $configlist) =~ s/floppy0=\K/$_/;
  open my $outfh, '>', "$_.config" or die;
  print $outfh $newfile;
  close $outfh;
  }
close $fh;