my @files = (.....some file names...);
my %hash = (....keyed upon file names...);
my @newfiles;

foreach my $file (@files)
{
   push (@newfiles, $file) unless ( grep{/\Q$file\E/}keys %hash );

   # pushes the name of $file to @newfiles if no match
   # is found to the pattern within keys of %hash.
}