Ok, you could try something like this:
Create a report footer that will print on a separate page. This page will contain information about what check numbers were used. I would put in it the print date, the starting check number parameter and whatever formula you're using to calculate the check number - because this is the report footer, this should be the last check number that was used (you may have to subtract 1 from it to get the right value - you'll just have to play with it.) You could also subtract the starting check number from the ending check number in order to get the number of checks printed.
-Dell