Here is an example of what you are looking for. If you go to any countdown page (mine is
/r/electronic_cigarette sig banner generator) and enter in the required info they'll give you the BBCODE for the signature banner. In that code is 2 things, the link to the picture and the link to their website.
Below is the link to the banner i created in the link above. The first block of text after the url= is the clickable link, the 2nd part is the banner image. Change the first link to your juice spreadsheet.
[ url=http://www.reddit.com/r/electronic_cigarette][ img]http://www.sigbanners.com/reddit/5369.png[/img]
(I added a space after the 2 left brackets ([) to prevent clickable link and picture popup)
Hope that helps!!
one more thing!!!! If you want people to have a better idea of what is at the link you can name it "click to see juices used" instead of your name, just an idea