Change AutoCOrrect list

I am doing a simple project on encryption. (Nothing top-security or high-tech!). I am using the AutoCorrect function in Microsoft applications to achieve simple substitutions. I have downloaded a free AutoCorrect program from the internet, but it does not function too well and sometimes crashes the computer. There are two parts to the program: They may be bid for separately or together. Part 1 I need a simple, reliable program that will substitute the AutoCorrect entries on the computer with another list which I'll create. (It would be less good, but also acceptable that it simply added to the current AutoCorrect list). The program must be easily installed in the common Microsoft platforms. I want to be able to create the list preferably in Excel if not Word. The list itself may be, say,100,000 words long. (Please inform me if there will be problems having such a long list). Example from list: Typed word(s) Substituted word a man xyxyxyx a woman xxxxxx xx Part 2 The AutoCorrect function will be on as the person types. Normally, (to the best of my knowledge), you can only reverse AutoCorrect changes individually using the Ctrl+Z keys. This will be too laborious for my subjects. I want to be able to have two options: 1. A button on the toolbar that will automatically reverse all the AutoCorrect changes in a document. 2. The AutoCorrect changes are automatically reversed when the user saves, prints, emails or forwards the document.