Here's a skip logic you can try:
Begin Unverified Perl
my $zipCodeQuestion = 'ZipCodeQ';
my %zipCodes = (
12345 => 1,
23456 => 1,
34567 => 1,
45678 => 1,
56789 => 1
);
return exists $zipCodes{GETVALUE($zipCodeQuestion)};
End Unverified
"ZipCodeQ" must be replaced with the name of the numeric question representing the zip code. Lines 4-8 should be copied and updated as necessary to check for all zip codes you want to match with this given skip. (If you have all zip codes in a simple list, an advanced text editor may be useful in adding the "=> 1," after each one.)
With your large number of zip codes, please test to ensure that the code is performing as quickly as you need.