Does anybody know of a macro that will highlight a specific number of words based on a numeric input in MS Word?

For instance, I would like to enter a number in a dialog box, such as 250, and have 250 words hightlighted in a document that I can then copy or delete.

I know I can manually highlight words to get a count, but I sometimes have to highlight an odd number such as 537 words, and I always either go too far or not far enough and it gets frustrating.

Thanks.