The 2015 rules permit having a single Classifier count in more than one division, if equipment and ammunition are suited to the other division(s).
See section 9.3 of the rules for details.
1.To make this work, what you're going to need to do is
2.Register the shooter in each division.
3.Score him in one division. He needs to be complete (all stages) in that division before the copy option will be available.
4.Open his (blank) score screen for another division.
5.Click the button to suck in the scores from the division you've already entered.
This way, upload to the IDPA website, Classifier history in ForScore, match results, etc. all work correctly.
Obviously, this needs to be done before the Classifier is "committed".
Here, Alex is registered in all five pistol divisions:
After his scores in at least one pistol division have been entered, you can choose to import those numbers into another appropriate pistol division.