Actually, you solution doesn't restrict itself to text having more than 40 words - it finds quotes of any length.

If one assumes an average word length of at least 5 characters, plus spaces, the following could be used:
[^0147][!^0148]{240,}*[^0148]
If that's too long for you, simply reduce the 240.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]