i did it! (yay!) .... turns out the 'AutopromoteCondition' hook was a red hearing.. what i needed was accomplished with the following line of code in LocalSettings.php:
#automatically add a user to a group (implicit rights of a group) based on the value of a session header variable from the host server security agent) if($HTTP_COMPANYNAME=="Acme") { $wgAutopromote['approved-user'] = array( '&', true, true, ); }
Thanks to all who helped and gave me some insights and things to try. Thank you! -Rich