Hi, I am the same expert who gave your the previous link.
That was indeed where you write to get an application to be on the show.
Here however, is some information on how you might be able to reach Bob Harper directly.
Here is a link to Bob's facebook page. You can go there and post a comment. I am told he reads everything that is posted personally.
Here is the formal Contact Us Page from Bob's website.
Here are Some email addresses to try: Whereby at one time these were reported to have been good email addresses, I cannot promise that all or any are Currently valid email addresses as things such as this change often these days. I also cannot guarantee that if your email actually reaches Bob Harper, that he will even actually reply to you.