If you check, you'll see that the footer columns have an order. The one on the right, is the bottom-most in the Footer Columns in Dashboard > Appearance > Menus.
But you won't see anything in there, as presently, your columns are generated by PageLines and WordPress.
So, if you copy the content of your right most column and paste it into a text widget, then add it to the Footer Columns sidebar, it will replace all the columns.
Then, you can add another text widget, labeled Sponsors, and post any message you desire into that widget.
You can then add the Latest Posts widget, then the Pages Widget over that, ending with a text widget containing your image in HTML code.
That will emulate all the current columns, but gives you complete control over what's in them.