#!c:\perl\bin\perl.exe -w

use strict;

my @csvlist = qw(file3 file6 file1 file10 file5 file2 file7 file4 file9 file8);
my @listofnames = qw(file1 file2 file3 file4 file5);

for my $x(@listofnames)
{
    my ($test) = grep { $csvlist[$_] =~ /$x/} 0..$#csvlist;
    print "$x found at index: $test\n";
}

##</code><code>##

file1 found at index: 2
file2 found at index: 5
file3 found at index: 0
file4 found at index: 7
file5 found at index: 4