Yes, that should be possible with some customisation. You could make a page plugin that's accessible only to Admin users, which has a form you can fill in their details.
Or a simpler way would be a plain PHP script you write yourself using the code from this docs page. You'd need to use the 'qa_create_new_user' function from qa-include/app/users-edit.php. See also here for more useful functions you can call.