I would love to show the voicings, but alas I do not know how to create the tabs online - if anyone reading this thread knows how to create tabs, any help would be appreciated. I suppose I can try to explain the voicing(s) in "long-hand" - I don't know how much sense this will make, but here goes.
D major voicing at 12th fret in Dadgad tuning:
Index finger (1) on the 3rd string 11th fret
Middle finger (2) on the 4th string 12th fret
Ring finger (3) on the 2nd string 12th fret
Pinky (4) on the 1st string 12th fret
The root of the chord (D) is on the 4th string. This chord form is one of the forms for major chords and it is moveable - thus, move it down two frets and you have the C major, move it up two frets and you have the Emaj. You can also play this chord with the middle finger on the 6th string (which is the same note as the 4th string)
To get minor chords from this chord form, move the index finger back one fret - so to get from D maj to D minor, move the index finger from the 11th to the 10th fret - this form is moveable as well. With the Am chord in "Friend of the Devil", you would move this minor form down to the 7th fret and your index finger would be on the 3rd string, 5th fret. These two chord forms are moveable and should get you into Dadgad. Remember the root note of the chord will be on the fourth and sixth string. Be warned though - once you start down the dadgad path, it is difficult to want to leave - for quite a while, dadgad became my "standard" tuning!
I hope this makes some sense - I wish I could give you the tabs, but as I said before, I don't know now how to create tabs online.