How do I set up a separate handling fee for certain items?

I have the newest version of ZC... I was wondering if there is a way to have a $5 handling fee (per order, not per item) added to the shipping cost when there are certain items in a shopping cart, but not have it added when there aren't certain items.
In other words, I am trying to set up my store to do MANUAL drop shipping (i.e. we get the order, and we place the order with the drop shippers.) Both drop shippers (for now) charge the same drop shipping handling fee of $5 on top of the shipping cost, but we have some of our own products as well that we don't charge the $5 handling fee for...:frusty:
I'm not sure what to do here, if it's something in the code, then that's fine, or if I can get some kind of module that will help, that would be great too.
ANY help will be greatly appreciated.
I have searched the forum, but I didn't find anything that was very helpful. Most of the posts were about automatic drop shipping.

Thanks!

In the shopping_cart class there is a function that you can test, based on the products table, how many items are in the cart:

  /**
   * Method to calculate the number of items in a cart based on an abitrary property
   *
   * $check_what is the fieldname example: 'products_is_free'
   * $check_value is the value being tested for - default is 1
   * Syntax: $_SESSION['cart']->in_cart_check('product_is_free','1');
   *
   * @param string product field to check
   * @param mixed value to check for
   * @return integer number of items matching restraint
   */
  function in_cart_check($check_what, $check_value='1') {

You could use this to test if 1 or more are in the cart ... then in your shipping module, you could add the extra charge if there is 1 or more ...

I don't need to check for how many items are in a cart, I need to check if "Certain" items are in the cart so that I can add a different handling fee for them, per order, not per item.
I have a different modeling "Scheme" for our items and the "Drop-ship" items. The ones for dropshipper A are HKI-##### and dropshipper B are HRV-#####. Our products are generally 5 letters (Except the gift certificates obviously, those are GIFT-###).
Is there maybe a way to specify, in a shipping module or something, the difference between our products, Dropshipper A's products, and Dropshipper B's products? Even if I have to go through and select which ones I want for the different rates?:frusty:
I don't know what to do...:cry:
Thanks for the reply though, Ajeh