Hello,
The links that you are talking about would be useful to insert into another website, so that someone could click on the link and be taken to your Auctiva store. If you don't have another website, then they really aren't helpful to you. If you could put such a link on your Auctiva store (and I don't think you can), if someone clicked on it, they would be taken right back to your Auctiva store.... where they were to begin with!
Remember, the Auctiva store is essentially a display of what is in your ebay store. It is not a stand alone website.
For the link coding that you are talking about, you need access to another website, blog, or similar "other" website/page. In other words, a place somewhere else that when the link is clicked, it brings the potential customer over to your store.
Hope this helps.