Automated Cancelling of Unmatched Bets

Hi,

Can anybody point me in the direction of a tool that can be used to allow the following:

*For each market you can set a specific time for unmatched bets to be cancelled automatically, e.g. 8.30pm. Ideally this could also be a pre-determined time before the market goes in-play, e.g. "Cancel bets 20 minutes before the market goes in play".

Obviously it would be preferrable if there was a free service available, but if not please could you indicate a rough cost asscoiated with such a servcice.

Thanks,