I'm sorry. I, too, am having a hard time visualizing this. Are you working top to bottom, or bottom to top?? The only place that you could logically pick up stitches from there would be down that diagonal where you have just finished increasing up to, but I don't get what your pattern means by "from bind off row to cast on edge".
Hmmmm, I just had a thought. Do you think that you're maybe supposed to pick up stitches along that little edge where you first started, ie. the first 2.5" of work that you did (that's the only other thing I can think of and it would go from your bind off at the armhole shaping down to the cast on edge :shrug: ). Does that make any sense at all??? By doing that, you'd be closing the armhole, but again I'm having a bit of a hard time visualizing it. Is there any way you could post a photo of what the finished item is supposed to look like?