[_m3]

So etwa?

use filehandle;
use strict;

my @eing = ("001", "003", "test", "mag");
my %filehandles;
my ($name, $filename);

die "Kein Argument angegeben!" if (not defined $ARGV[0] or $ARGV[0] eq '');

foreach $filename (@eing) {
	my $fh = new FileHandle;
	$fh->open("> $ARGV[0]\.$filename") or die "Schreibfehler bei '$ARGV[0]\.$filename - $!\n";
	$filehandles{$filename} = $fh;
}

foreach $name (keys %filehandles) {
	print {$filehandles{$name}} "$name\n";
}

foreach $name (keys %filehandles) {
	$filehandles{$name}->close;
}