The xbox, in it's softmodded state, will still boot as long as the DVD drive logic board is connected. So, start it up and just ftp a copy of your evox dash to C and rename it to evoxdash.xbe. When that is done, open your ind config file in a text editor and make sure there is an identically named listing for that executable in your ind config so the bios knows the dash name and where it is located.
Toward the bottom of the config file, edit the first dash entry so it says C:/evoxdash.xbe
You now have a dash for your new bios to boot after it has been flashed to the TSOP.