use File::Find::Rule;
my @filenames = qw[ sample.txt sample123.txt  ];
my $reFilenames = join '|', map quotemeta, @filenames;
$reFilenames = qr/$reFilenames/i;

my @files = find(
    'file'     =>
    'name'     => $reFilenames,
    'maxdepth' => 1,
    'in'       => $dir
);