Importing list of users into a project

Question

I was wondering if there is a proper way to add a large number of usernames to a project?
The scenario is this. We have translators that would like to share their BT’s for use as resources by other translators working in the same part of the world. There would probably be over 50 users to add, making it cumbersome to add the users one by one to all the BT projects.
I needed to add a bunch of observers to a Consultant notes project that we are using for resource notes, and found that I was able to run a regex on a list of usernames, and then paste that into the user access xml file. That seemed to work fine, but is a bit cumbersome, and I figured there might be a more straightforward way that doesn’t require knowledge of regexes, etc.
Thanks
BEH