Manipulating Page Numbers - Help !!!

I have a report that is grouped (its actually a set of invoices) and I want to restart the page number at the beginning of each group(invoice).

I have tried writing macros that 'remember' the reports 'currentpage' number on the header page of each group and substracting it from 'currentpage' number to make my own page numbers.

Unfortunately linking the macro to the create group header/footer event does not appear to work for me as a trigger to reset my page number counter.

Anyone any ideas/experience tweaking page numbers?

Thanks in anticipation .....