Excellent – I done it through creating a custom field and editing the slider.php field with the following value straight after the </H2> tag:
<?php $key=”SubHeading”; echo get_post_meta($post->ID, $key, true); ?>
The best thing about this is that as it is already in an existing loop, the sub-headings change for each post on the slider to correspond with each article.
Thanks very much to you both! Much appreciated. ??