Ok, i dont want this to sound insensitive, and i do apologise if it comes off the wrong way.... BUT
If there you have a, for lack of a better word, stump instead of a index finger, perhaps you could get a
slide(perhaps fabricate a wodden one), and fit that over the "stump" and A) use it to fret barre chords, and play slide
Again, i apologise if im just being sick, i dont mean to be, its kinda just my way