# assume that $dbh is ready...

my @places = qw/Otago Auckland Northland Boolaboola/;

my $query = <<ENDSQL;
SELECT c_mail, c_first, c_last
FROM tblClient, tblGroup, tblRegion
WHERE tblGroup.g_name = 'motel'
AND tblRegion.r_name IN
ENDSQL

my $sth = $dbh->prepare( $query . ' (' . join(',',map{'?'} @places) . ')' );

$sth->execute( @places );