I have converted the Winged Twilight and the Ash Ghoul, if you find
anything weird let me know :)
p.s you have to add them to the CS yourself :)

download link for the Ash Ghoul:
http://www.mediafire.com/?js8j7ig8fisbgbg
download link for the Winged Twilight:
http://www.mediafire.com/?8auazcdvdz24ldx

download link for the Ash Ghoul:
http://www.mediafire.com/?js8j7ig8fisbgbg
download link for the Winged Twilight:
http://www.mediafire.com/?8auazcdvdz24ldx

^ here the active sequence name is Forward. See the same line for the special idles in oblivion creatures.
The priority is present in nifscope under controlled blocks as "Priority Byte". See this for detailed instructions.
I don't think that special idles use any sequence tags apart from start\stop (which are automatically added).
But anyways you can also have a look at sequence tags in nifscope. Here are detailed instructions.