You can add a polygon to Skyview.
Check out step 8 of this guide:
(Bake a Pi)
This is a json file but if you are handy with formats, maybe you could convert your format? 
You might also want to read this thread (Skyview - customize data presentation),
which is mostly about GitHub - alkissack/Dump1090-OpenLayers3-html: Modifications to the OL3 html files (part of the dump1090-fa branch)