Can you try this: http://xdaforums.com/showthread.php?t=2373410 ?
I recall adding support long back.
Are you using TWRP? Or CWM? TWRP installs never fail unless you're installing on an unsupported device (a device that is not the Nexus 7 2012 Grouper/Tilapia).
I haven't tried it myself. But I'll try tomorrow (or ASAP) to create an ADHOC network from my Windows 7 distro and let you know. I think ADHOC networks are supposed to show u pnormally in the WiFi section of Settings.