Unfortunately there is no way to go straight to the last page to preview it using Series 7. Using the upcoming Visual Builder V8, which we expect to release this year, there is a new 'go to last page' button.
For the time being you could try installing a free PDF driver such as Primo PDF (the last time we checked this, it does not work on Server 2003 however), and print your report as a PDF file, then use Acrobat Reader to open the last page of your report.
http://www.primopdf.com/