As you may have come to find, Release versions and WIP builds distributed by DeSmuME developers do not have the WIFI menu enabled, while builds provided by dodgy scener sites or the one your bestest friend in the whole wide world has handed to you on a usb key does.
Officially, DeSmuME DOES NOT support the use of builds with WIFI support.
As such, though it may come as a shock to you, requests for help or information about it are thus NOT likely to obtain a response to your satisfaction.
Threads pertaining to this may be closed, users banned, families killed, it all comes down to the administration's mood at the point in time they come across such a thread.
The developers have no current interest for furthering development of the EXPERIMENTAL_WIFI, and the current state of the DeSmuME source code might have even completely broken it.