MySQL, at least, supports the IN() clause. For example, I just ran a query:

select title from node where node_id in (1, 2, 3);

+----------+
| title    |
+----------+
| nodetype |
| node     |
| setting  |
+----------+
3 rows in set (0.05 sec)
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If your database supports that or something similar, you can build a clause resembling and table.column in ('PND', 'NEW').

my %possibleArgs = (
    1 => 'NEW',
    4 => 'PND',
    9 => 'CLS',
);

my @args;
for ('col1', 'col2', 'col3') {
    if (exists($possibleArgs{$_})) {
        push @args, $possibleArgs{$_};
    }
}
$extraqueryarg = "and table.column in (" . join(',', @args) . ")";
[download]

Something similar to that would do the trick.