Additional links from product-A to product-B?

Hi is it possible to add an additional links inside the BODY of Product info page? (links at header, footer or sidebox is not my case, I really want this link near the Attribute area)

I try to do this by edit the tpl_product_info_display.php. But the link I added will show on EVERY product info pages... :(

My case is, I want there is an individual link on the product-A info page, this link points to the page of product-B. But product-B have a different link point to product-Z, etc. (A, B and Z all in the same Catalog)

The most perfect solution of my case is, how to trun a Attribute to a link? For example a radio style attribute of different color set, when customer hit the black color radio button will let him go to the page of product-black.
I know it's not quite possible and I am too greed to customize my site well. However, I ask this just because I saw there's a kind of Attribute option type called "link" (the bottom one). I wonder what this for and can't see any info about this option type here?

Thanks and sorry for my poor English! :P

See the cross sell options
http://www.zen-cart.com/index.php?main_page=contrib_search_result&search_in_description=1&keyword=cross+sell

kobra:

See the cross sell options
http://www.zen-cart.com/index.php?main_page=contrib_search_result&search_in_description=1&keyword=cross+sell
Thank you very much Kobra.

The function of cross sell mod is exactly what I want. However I'm still prefer there is just a simple text of link, instead of "many stuffs inside a center box"..... Because my site it's layout design is Simple and Clean. Beside the main product image, there are no box, no button, no border... everythings looks just a different color of text.

Anyway, I have to send a BIG THANKS to your kindly advise. I will try my best to modify the CSS let see how clean it can! :blush: