You can read about this flexible new option in this NewsWire article .
Many applications keep a running total in the master record of all the detail transactions.
You can use the latest feature in Suprtool to easily do this. Now let's update the master dataset records. It contains a clever way to do mass updates by generating a Suprtool task for each update value. Perhaps it will give you ideas for solving other problems. Suprtool does not currently have a command for this operation.