Duplicates - allow for REPORT based on a workshop to show duplicates

The Merge Duplicates option under Contacts is great but a Report that could do the same as the Merge Duplicates but filtered by a workshop ID would be so so so much more useful. We have a large number of duplicates thanks to an old database that was imported and simply don't have the time to work our way thru it - if we had a report that looked for possible merges within a single workshop it would make things so much better