Not sure how to go about that, but I'd image you could easily add the data to the header of each page so search engines index it. You'd need a custom plugin to do it and CB certainly has API to manipulate the header of a page.
Example (assumes $user object is present and global $_CB_framework established):
[code:1]
$_CB_framework->document->addHeadMetaData( 'description', 'username: ' . $user->name )
[/code:1]
Obviously developing a plugin and utalizing the API is not something for someone new to CB, Joomla, or PHP in general. I do recommend reviewing other plugins available and seeing how they're structured.
We do provide a very simply helloworld plugin in the downloads section to assist in plugin development as well. You can also review tutorials in my signature for information on CB API usage.