I don't see how you'll get around the list of regulars. You can maybe make it slightly more efficient with something like $y = $1 if $x =~ m/(host1|host2|host3)/i perhaps; but, I think you'd need Benchmark to see if that actually helped.

If it was my code, and I was getting more than a few dozen lines or so, I'd probably start a table of pre-compiled host regulars or something like so:

# e.g. $hosts{'DMZ Server'} = qr{(?i:server2)};

while( my ($name, $reg) = each %hosts ) {
    return $name if $x =~ $reg;
}
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Update: I just noticed this little bit, "separate the comment list from the actual script" You can definitely build the hash in a separate file like below, but I think if your list is getting really big, you should look at the packages mentioned in the post below mine. Both are pretty slick.

use MyHosts;

while( my ($name, $reg) = each %MyHosts::hosts ) { }

# ...

package MyHosts;

use strict;

our %hosts = (
  'Server Name' => qr(?i:serverpattern),
);
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