[Warwick]

I finally found out how to go about this matter

TIP: I came across a big part of this modification somewhere in the forums and copied and pasted the code I found there; somehow this copying and pasting didn't make it to work, finally I went through the steps described below (go to the site, enter url etc. etc.) and succeeded.

>> The not properly functioning of copying and pasting of code could be forum related so I would advise you not to do this. <<

Technical specs
X-Cart version: 4.1.3
Other versions could work with this tutorial, but you'll have to try and see for yourself!

To make thing really easy (you can skip step 1 and 2 with this); here's the logo so you don't need to download it:
http://www.trustlogo.com/images/cornertrust.gif


Step-by-step setup

1. Go to: http://www.instantssl.com/ssl-certificate-products/ssl-certificate-corner-trust.html on this page you will sees Comodo's 'Corner of Trust' logo in the right bottom corner and how it works; scroll and you'll see it stay exactly in the same place. On the page itself you can read additional information about the 'Corner of Trust'.
2. Download the 'Corner of Trust' logo by right clicking on it and performing 'save to disk' under its original name (cornertrust.gif).
   
3. Create a directory with the name 'comodo' in the root where you have installed your X-Cart.
   
4. Upload the 'Corner of Trust' logo to the 'comodo' directory; retain it's original name (cornertrust.gif).
   
5. Go to: http://www.trustlogo.com/ssl-certificate-support/index2.html
   
6. Fill in the the exact graphic url at step 1 (example: http://www.yourdomain.com/shop/comodo/cornertrust.gif) where 'shop' is the name of the root directory where you have installed X-Cart and 'comodo' is the name of the directory you have created and uploaded the cornertrust.gif logo in.
   
7. After having filled in the exact url where the logo is situated, click on the arrow that is right beside the text 'Enter your graphic URL here:'.
   
8. If you have provided the correct url, your 'Corner of Trust' logo will appear automatically underneath.
   
9. Continue to step 2 and copy the javascript code under 'Snippet 1' it should look something like

   <script language="javascript" type="text/javascript">
   var cot_loc0=(window.location.protocol == "https:")? "https://secure.comodo.net/trustlogo/javascript/cot.js" :
   "http://www.trustlogo.com/trustlogo/javascript/cot.js";
   document.writeln('<script language="JavaScript" src="'+cot_loc0+'" type="text\/javascript"><\/script>');
   </script>

10. Open /skin1/customer/home.tpl and paste the copied code directly after </title>
    
11. Put {literal} before the <script language="javascript"*type="text/javascript"> part in the code that you have just added.
    
12. Put {/literal} after the </script> part in the code that you have just added. So that the newly added code will look like this:

    {literal}<script language="javascript" type="text/javascript">
    var cot_loc0=(window.location.protocol == "https:")? "https://secure.comodo.net/trustlogo/javascript/cot.js" :
    "http://www.trustlogo.com/trustlogo/javascript/cot.js";
    document.writeln('<script language="JavaScript" src="'+cot_loc0+'" type="text\/javascript"><\/script>');
    </script>{/literal}

13. Go back to http://www.instantssl.com/ssl-certificate-products/ssl-certificate-corner-trust.html; copy the code at 'Snippet 2' it should look something like

    <script language="JavaScript">COT("http://www.yourdomain.com/shop/comodo/cornertrust.gif", "SC2", "none");</script>

14. Go back into skin1/customer/home.tpl and paste the code from 'Snippet 2' right before </html>.
    
15. Put {literal} before the <script language="JavaScript"> part in the code that you have just added.
    
16. Put {/literal} after the </script> part in the code that you have just added so that the newly added code will look like this:

    {literal}<script language="JavaScript">COT("http://www.yourdomain.com/shop/comodo/cornertrust.gif", "SC2", "none");</script>{/literal}

17. That should be it.

My 2 cents

No garuantees or support; I'm sort of a newby.