You’ll have to create a separate page template for each custom sidebar you want running.
Once you’ve done that, you need to create your custom sidebar templates. Name them something that allows you to remember what they contain.
For example, let’s create three different sidebars in addition to the default sidebar.php:
contact-sidebar.php
about-sidebar.php
custom-sidebar.php
In order to pull those in on the page we want them, we’ll need to create three different pages. They don’t have to be different other than the call to the specific sidebar, but they can if you need them to.
Don’t forget to put the custom page code at the top of each, like this:
<?php
/*
Template Name: Custom Page Name
*/
?>
Then for each custom page template, find this code:
<?php get_sidebar(); ?>
And substitute this instead, using the name of the desired sidebar template you just created:
<?php include (TEMPLATEPATH . '/custom-sidebar.php'); ?>
That way, each custom page has its own custom sidebar. There may be an easier way to do this, but that’s how I’ve done it on my site as well, with a custom sidebar for my contact info on my Contact Us page. ??
HTH.