You can link the checkbox to Word's VBA, then have that macro modify the file's properties, link those file properties to a variable in the datacard. Pretty easy going in that direction.
Going the other way, the datacard driving checkbox would be harder. You would need a trigger to look at the file properties and then set the checkbox accordingly. I think I would use the "Document_Open" event.
Thanks for the help Jeff. Unfortunately I have little experience in programming and the option that I'd need to take here would be the datacard driving the checkbox in the word document.
I think I may have to leave this, or I may ask one of our software engineers if they'll take a look at it. Unless do you know of any good source material which would help achieve my goal using the "document_open" event?
It's not essential to my process but I'd of loved to have the variables mapped to EPDM to allow for searches to be carried out on these.