I see what you mean. This fuji S5700 is not able to have the lens replaceable ( your main lens is permanently fixed onto this camera body ). The Anscor lens that you are seeing at the ebay is only attaching to the front of your existing lens by thread ( if I am not wrong ).
Personally, I have not used any of these, so... cannot comment too much. It is best that you try to mount the lens before you start paying for the lens, else the risk is all on your side. :sweat: