Full-size additional product image

I need to modify the product page layout to display only the full-sized version of an additional product image (there will only be one additional product image per product) below the product description, rather than the rollover thumbnail swapping out the main product image.  I'm new to ASP but feel comfortable working through the code-- but I can't figure out what string to use to just display the large version of the additional product image for that product.  I would assume there is something relatively simply I can put in place of "pcs_AdditionalImages" in viewPrdL.asp, or replace the scripting language in the viewPrdCode.asp file in the Additional Images section with something simple?  Hopefully?

Any help would be appreciated!