It seems like you don't need to define exactly what characters can go in your value. You just want what's inside the single quotes after 'cusip'. '(.*?)' means the shortest possible string between two quotes (so the text 'ab' cd' would yield "ab" and not "ab' cd").

But it looks like you are trying to parse JSON. If you need to get more than one value from your string, decoding the serialized data into a perl structure may be more helpful. JSON is pretty easy to use.

Edit: Corion pointed out that the 71-24 doesn't look like serialized data (or at least not JSON), so while this could still be valid javascript or python code, JSON may get confused.