Store s2 custom fields

// Populating custom fields after registration
function ch_s2_registration_field_population() {

    global $current_user;
    get_currentuserinfo();

    // Do only at the first login of the user
    // if ( get_user_field('s2member_login_counter') < 2) {

        $s2user_country = get_user_field( 'user_country' );
        $um_country         = get_user_meta( $current_user->ID, 'user_country', true );

        if ( $um_country == '' && $s2user_country != '' ) {
        update_user_meta( $current_user->ID, 'user_country', $s2user_country );
        }

    // }

}
add_action('wp_head', 'ch_s2_registration_field_population', 10, 2);