Terminate a workflow "in progress" via a workflow

I have a workflow that launches when an item is created or updated. The workflow sends an email then pauses until a date is reached (date is specified by field within the item). Once the date is reached it carries out ar a few more actionsthe completes. I would like the workflow to be stopped and the relaunched (effectively restarting the workflow) when an update is made to the item. I have tried a number of solutions but it seems as though the workflow cannot be stopped / terminated while it is "in progress" unless manually done so via the browser. Is there anyway I can stop / terminate / cancel (or any derivitive of that action) an "in progress" workflow?