I think this is what you are looking for:
http://codex.wordpress.org/Function_Reference/update_user_meta
Here is a example of how this can be achieved: http://inchoo.net/wordpress/programatically-add-metadata-to-user-accounts-in-wordpress/
I think this is what you are looking for:
http://codex.wordpress.org/Function_Reference/update_user_meta
Here is a example of how this can be achieved: http://inchoo.net/wordpress/programatically-add-metadata-to-user-accounts-in-wordpress/