I'm not aware of anyone doing any significant work reverse engineering the phone app protocol. This could be a productive area for exploration.
The cameras use UPnP + PTP/IP for connection to PCs, but from the firmware it's clear phones use a different protocol. I looked into the PTP/IP extensively (https://chdk.setepontos.com/index.php?topic=10724.0
) but didn't didn't ultimately get anything really useful working.
But I just have to say it (given that its 2018 now) - a Windows Phone? Really?
We cater to people running BASIC on 10 year old P&S, so I wouldn't throw too many stones
That said, the programmer time required to reverse engineer the protocol and create a compatible client would certainly exceed that of a top of the line android or iphone.