There is a module that does just that actually. It is called DNNMasters Membership Management Suite PRO. I have succesfully used this module from DNNMasters. you can find information HERE . It can pe programmed to run a preset import routine based on a schedule. I will also say that I have purchased over 50 different modules for DNN myself and the developer of this is top notch. He (Chris) is responsive to support requests and in every case had the exact solution for my problems (most of which were my own fault) This pachage is A+ and I have gotten his subscription and use just about every product he offers. they help to manage complex portals and make bulk user and permissions a snap.

Mark

I would suggest that you direct the questions to Chris's web site. He has a forum and he will answer questions. He has a very deep knowledge of the user stuff. I spoke to him about your needs and he said that the exact functionality you want is not in their module at this point but they are planning on adding it. It is just a issue of time. I do think if you can find an acceptable plan for syncing that wasn’t quite “live” it might work, but that would be for you to decide. I know I used it for some things that just would not have been possible without his modules.

Good luck with your search

Mark