Just thinking aloud here - is this something that your RMs would need to do on every submission and does the search itself need to be something they do manually? Or does the report just need to get to them. Also, does it have to happen immediately for each submission or just soon? If it's something that would always happen, you could have Workflow run the search itself and then email out WA links or Client lfe files that will open up to the search results already there for each relevant entry. Then you don't even have to worry about messing with toolbar buttons.

That said, you could certainly make a toolbar button to perform this sort of search in the desktop client, taking the current entry as a parameter and then using CAT to open up the Search UI with the results. Depending on the type of search you need to do, you might able be able to just create a custom quick search within the desktop Client or Web Access that would handle running a search around a provided critera (user inputted in that case). Both of these are client side items though so would need to be pushed out to individual workstations - that's one reason I was asking about the possibility of using Workflow, since that can be centrally administered.