Thanks again - I made the correction and it has helped a lot.
The search tool is still reporting 'extra' documents though. For example, I entered "QP.01.020" and got back documents with "Q
A.01.020" and "QP.01.0
10". All of the documents with exact text were found (which is great!) but I have to open all of the documents individually and manually filter those that only have partial matches.
Unfortunately, the "X.##.###" numbering format is used for all of our company document names and has been too widely distributed to easily change (otherwise I would just simplify it and move on!).