How to reset data prev next counts on table

I have a portlet that runs a service that creates an async table of data. A DataPrevNext object has been added to the table so users can go forward and backward through the online “report”. There is also a (useless) async command button called “Refresh” that does nothing. I want to code the “refresh” button to reposition the data in the table back to the very beginning of the data. I’d also like to program a command button that “clears” the table and clears the values held by the DataPrevNext object.
Does anyone have any ideas on how I can do either of these things?
(using Designer 7.2)