Hi,
You can use the built in PHP substr function.
function.substr.php
On a standard field this would read something like.
<?php echo substr($row_rs['fieldname'],0,50); ?>
I dont use PowerCMS but im guessing something like
<?php echo substr(WA_getCMSContent($database_PowerCMSConnection, $PowerCMSConnection, 'Home Page' , 'content'),0,50); ?>
might work?
Cheers
Ian