I think what I would do is build a list of the prefixes and suffixes around the exclusions of 'ALPHA' -- in your case, @prefixes would be ("_", "#", and "CAW5 ") and @suffixes would be (). Then I'd produce a regex from those: 
my (@pre, @suf);
for (@exclusions) {
  my ($p, $s) = split /ALPHA/, $_, 2;
  push @pre, $p if length $p;
  push @suf, $s if length $s;
}

my $pre_rx = join "", map "(?<!\Q$_\E)", @pre;
my $suf_rx = join "", map "(?!\Q$_\E)", @suf;
my $total_rx = qr/${pre_rx}ALPHA$suf_rx/;

[download]
Now you can match your strings against the pattern in $total_rx.
Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

In reply to Re: Pattern matching when there are exception strings by japhy
in thread Pattern matching when there are exception strings by Moron

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