Does anybody know how checkbox results are stored in Word?

What I'd like to achieve (if it's possible) is for a scan from outside word to be able to determine that if a checkbox formfield is checked, ignore the next 30 characters or so in the form. It's just a crude mechanism for cutting down on the numbers of false hits in a very wide text search. And false hits are derailing a text search project on which a lot of time and money has been spent.

A Word/VBA solution is not possible, because a search can potentially be across over 1 million documents.

I've had a look at a document in notebook, and have found the string "FORMCHECKBOX" where a checkbox has been put into the document. But I don't have a hex viewer, so can't tell if there's a hex value close to the FORMCHECKBOX field which is changed when a checkbox is filled in. It does look as if values elsewhere in the document change, so I don't think my chances are good!

My time limit on an answer to this is short, as we have to go to management tomorrow and say yes or no.