How to make an image not appear broken using BBCode?

As this is my first thread, I'm not sure if this is the forum to be asking this, so please forgive me if it's not and feel free (mods) to move this to the appropriate forum.

I understand how to use the htaccess method to transfer a fake image to your affiliate link, but I don't know how to use BBCode to get the image to not show up as broken. I know that with HTML, you can set alt="", but how would you do this using BBCode? Or is there some other way to do things so that the image doesn't appear broken? Hopefully I'm explaining this well.

I appreciate the help guys.

Yeah.. this should be in the CS section...

Yeah.. this should be in the CS section...

I think there is no way to do that if you are referring this to cookie thingies