Autocomplete words in document (Guru's)

Hi Gurus,
Does anybody got an idea (better yet an example) of how can I make an application that autocompletes word inside a document ? (Like intellisense but with regular dictionary.).
And how can I get access to a dictionary file to use it from.

I know it's quite a challenge...
Thanks!

It can probably be done but it will become unusable as the list will be enormous. If you type in "a" you will get everything from "a" to "arithmetic to ??? This is the reason that MS didnt make its autocomplete work that way. They do it after the word is spelled.

Moved

My intention was to enable this functionality only after typing 5 letters or on specific request.
Any ideas ?

I dont have Office installed yet, had to reinstall entire system due to HD failure, but there was something in Words Autocomplete dialog window about using specific or custom dictionaries.

I should have my system mostly installed tomorrow. :(

Thanks,
Please notice that this application is intended not only for the microsoft office application but for all areas with text on it.

Oh, ok. Sounds like its going to be a difficult program to program but helpful if you get it.

Yes it will...
Any ideas ?