Change selection criteria in real-time for "select"?

    Dec 31 2008 | 2:29 pm
    I want to do something simple: Uzi is generating a few random numbers, but I want to filter out some of them. Those that are in the filter will be stopped, the rest will be passed through as numbers.
    Is there a way to make "select" change its filter settings? It doesn't seem so.
    For instance, I want to stop "4" and "5" from the Uzi stream at one point, then stop "7" and "8" in the next etc.