Programmatically import users and create each for them organic groups
Your explanation seems a little bit confused. Creation of an OG is as simply as creating a node.

So from what I understood you wish :


Get a user data from external source (how you perform this ? by cron ?)
Create a group for each user
Assign that user as group admin ?


Is it what you want to perform ?

Also take a look here :

http://drupalcontrib.org/api/drupal/contributions%21og%21og.module/7