Adding a set fee at checkout

I’m completely new to wp and I did try to find the answer using the search feature, but no such luck. I am using 2.5 free wp with ecommerce for my website. I sell a physical product through a drop-shipper. My drop shipper charges a handling fee per order (not item). Instead of kicking this cost back to my customers via product pricing, it would be much simpler to add a flat handling fee at the time of checkout but I can’t find out how to do this. Is it possible? if so, how? Also, I did find an area where there is a “Merchant note” and I tried to place my blurp about paying said handling fee at time of checkout, but that feature did not work – doesn’t show up anywhere, anyone know how to fix that as well?