Digital Sandwich

I was toying around with regexs this morning and learned a few things I had just never taken the time to learn before. In any case, I came up with this:

#((?:(?<!\\)\"(?:(?:(?:[\x20\x09]*[\r\n])?[\x20\x09]+)?(?:[\x01-\x08\x0b-\x0c\x0
e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e]|\\[\x01-\x09\x0b-\x0c\x0e-\x7f]))*(?:(?:[\x20\
x09]*[\r\n])?[\x20\x09]+)?\"|[^"(]+|\\["(]|^)+)(?:(?:(?:(?:(?:[\x20\x09]*[\r\n])
?[\x20\x09]+)?(?P<comment>\((?:(?:(?:[\x20\x09]*[\r\n])?[\x20\x09]+)?(?:[\x01-\x
08\x0b-\x0c\x0e-\x1f\x7f\x21-\x27\x2a-\x5b\x5d-\x7e]|\\[\x01-\x09\x0b-\x0c\x0e-\
x7f]|(?P>comment)))*(?:(?:[\x20\x09]*[\r\n])?[\x20\x09]+)?\)))+(?:(?:[\x20\x09]*
[\r\n])?[\x20\x09]+)?|(?:[\x20\x09]*[\r\n])?[\x20\x09]+))#

(of course ignoring line breaks.) An 'atta boy' (or girl as the case may be) to anybody that can tell me what this would be used for .