While changing the data-gathering would seem to me the logical steps, I do think there should be an alternative which requires - in your case - less changes.
Doesn't the SUMMARY clause work both in preview and when you print?
The actual steps to take would depend a lot on how you invoke your reports. For example, if you have a specific form where the user selects options and then clicks either on "Preview" or "Print", you could hard-code the commands right into this form. Similar with a PRG.
If you have a class that handles your reports, additional adjustments may be needed.
>Sure, but I have a report that's working fine as-is.
>
>I'd like to make it so that whenever anyone invokes it, it will be SUMMARY.
>I really don't want to change the data-gathering for the thing.
>
>Looks like no way, though.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)