You need to contact an experienced DUI defense attorney in Mass.
They would be best positioned to see if there are some legal arguments that can be raised or if they can assist you in resolving this old case.
If there is no warrant it is unlikely that it really is an open case. But you could contact a lawyer in MA to review and see if it really is open, and see what can be done to resolve it. A statute of limitations defense prevents filing after a certain date, this is not a statute of limitations question.
This response does not create an attorney client relationship and is offered for informational purposes only. Only a lawyer fully versed on the facts and circumstances of your case can properly advise you on the case. I am licensed to practice in Minnesota, not every state. You should always consult with an attorney licensed in your area on how best to proceed.
I agree with my colleagues. Contact a MA criminal defense attorney in that area to determine whether the case is, in fact, open. If the charge is still pending, given the age of the case, s/he may be able to convince the prosecutor to reduce or dismiss the charge. As a former prosecutor, I can tell you that due to witness inavailability and vast changes in DUI law and testing technology, that case will be nearly impossible to prove.