Handling MS Word events in VB.net

[ENTBedford]

My app starts Word, opens a new document, gets data to fill in demographics, then hands the doc to the user to type the body text of a letter. User then returns to the app to get another set of demographics, then returns to to Word to type another letter, and so on till finished. So far so good.

At present the app checks if Word is running and Doc is open for each new letter and restarts or opens a new doc if required.The danger is that the user can still close Word or the Document before copies have been saved etc so I need to get my app to control Word closing itself and docs.

I need to refer to the Word application in many places, so have been using:
"Public oWord as word.application" at the start of code, then when required:
oWord = new word.application to start an instance of Word to use.

Using "Public withevents oWord as word.application" and a sub to handle events seems to be the way to keep control of Word, but gives an error when I try to open an instance of Word (oWord = new word.application) later in the app code. Does using "withevents" mean that I can only reference that specific instance of the word.application?

Clearly I am doing something stupid, but what?