Thanks a lot - I've actually just got it working - if anyones interested this seems to be doing the job:
<?php $tits = get_the_title(); if ($tits == "The Living Map of La Bastide") {$add = "http://www.labastidevivante.fr\" target =\"_blank";} else{$add="http://www.samwoolf.net/mfreeth/category/".$tits;} ?>
<h2><a href="<?php echo $add; ?>" title="<?php the_title(); ?>"><?php the_title(); ?></a></h2>
I think thats basically the same as what you were telling me about echoing.. except that the the_title() function seems to have echoing built into it so once I started using get_the_title() instead it all fell into place.