I think it would be possible, but it might be a bit more work than you anticipated. There are several things to remember about NAD and passwords.
As you probably already know, the passwords reside in the password.bin file in the application directory. For NAD, this will be at least 2 places; the master application directory and the local working directory on the remote node(s). When a user changes their password on a remote node, it will only change it in the password.bin file on that node, which then gets overwritten the next time you load the application. One way around this is to use scripting in the app that copies the password.bin file from the node where the user modified it to the master application directory. This would be the first part of the solution.
The second part of the solution would be to propagate the password.bin file from the master application directory to the other remote nodes. This could probably be done by a simple batch file that runs periodically. You can simply copy and overwrite the file on all the nodes. The drawback to this is that if the designated directory on the remote nodes ever changes for some reason, you would need to update whatever automated solution you have in place.
Hope this gives you some direction.