A while back I tried to hack the dashboard. I even posted a video here. But I don't have it anymore. I was able to boot EvoX (not correctly, in the "Safe" mode only) but I just gave up.
I used the Live updated dashboard, and I renamed the variable "xbox live" in "evox dash" and pointed to the path of EvoX.
It worked, not really correctly, but hey, I could go to my evox without using IGR directly from the original dash!
Since I really suck in ASM (huh? what's that?), C++ or other shit, I couldn't help you.
It's a really nice project you're building.