# ... as before, set $jar = ...

sub callback {
    #  0  version
    #  1  key
    #  2  val
    #  3  path
    #  4  domain
    #  5  port
    #  6  path_spec
    #  7  secure
    #  8  expires
    #  9  discard
    # 10  hash

    #-- add more comparisons to narrow the search result
    print "Cookie: $_[2]\n"  if $_[2] =~ /^8430/;
}

$jar->scan( \&callback );