cpt-order-columns-switch.php

<?php
	switch( $orderby ) {
		case 'fp_sf_tot':
			$query->set( 'meta_key', 'fp_sf_tot' );
			$query->set( 'orderby', 'meta_value_num' );
			break;

		case 'fp_pdf':
			$query->set( 'meta_key', 'fp_pdf' );
			$query->set( 'orderby', 'meta_value' );
			break;

		case 'title':
			$query->set( 'orderby', 'title' );
			break;

		default:
			$query->set( 'orderby', 'menu_order' );
			break;
	}