I run into this issue every now and then.... as I am today.
I have a billing report that summarizes by client and job. Simple enough.
But now I need to add a flat amount to the summary of the report.
In this example they want the Overhead amount listed at the bottom of the report like this:
Overhead is a separate table where they enter rent, services, etc. by month.
I experimented with Copy&Paste of summaries into global fields in the trailer summary.
It works but I am curious for other ideas.