Making a minor alteration to windows .exe file

I am not a programmer. I’m a doctor and I work with patients (adults and children) who have learning difficulties (particularly difficulties with reading). I have developed an .exe file which helps our patients practice reading texts on a Windows screen. I have the source code. This is how it works. When the text is on the Windows screen and the patient comes to a word they can’t read they simply double-click on the word and that single word is immediately highlighted and read aloud. This allows them to carry on reading without interruption. In trials we have found that the program works well but there is a minor problem. Because our users have learning difficulties they do not always do an efficient double-click when the cursor is directly on a single word and as a result a whole paragraph or whole line is highlighted. We find that this causes them to lose confidence and they then think the whole program no longer works and they stop trying. I would like the program to only react to an efficient double-click when the cursor is on a single word. If they do an unusual click and nothing happens they are likely to try again and will slowly learn that only an efficient double-click on a single word will work. I believe fixing this problem is likely to be a small job and if you think you can do this we can chat.