Had to do a little freehand scribbling to remove some company stuff and extra distracting functionality, but I'm pretty sure this will still work. Execute the code thus:
$ php email2uer.php jdoe
It should just come back with something like:
johndoe@yourcompany.com
(or warn you that this user id isn't in the Phabricator SQL database...)
Then use it however you'd like. Thanks Chad and staff for your patience.