You should use a group. You go to the Insert-> Insert Group. That will insert a group on your report and will open a dialog asking you which field to group by which would be your Product Code field. T
There are a number of ways to sum the total but the easiest I believe will be for you to place the quantity field in the detail section. Right click on that field and select insert summary field. It will open a dialog box and select place summary in group footer.
If you dont want all the Quantity fields to show, move the blue section on the side of the report and right click on Detail section and choose suppress section. (You can also use the Section Expert for this.
What you end up with is
Group Hdr Product Code
Detail Quantity ( this wont show since its suppressed
Group Ftr Total of Quantity for that product code.
There are things you can do with placement like moving the Product Code field to the Group Footer if you want it to show on the same line as the summary and so on.
Hope this helps
Regards,
John W.