Without Trados Studio it does not currently seem possible to create a new report at will - only when files are added - or to create a single report on all files (if source files are added in batches).

Our situation which calls for this is when we add a second batch of files after work has already started on batch 1 and want a single report that encompasses all files so far added, but the original match totals (words) from the first batch should be reused (we don't want the totals in the second batch to be affected by the work already carried out on batch 1).

Perhaps I'm missing something, but it's not clear that this is possible.