I'm trying to average the values in approximately 250 non-adjacent cells
(there is no pattern to the cell location).

My first obstacle was the 30 argument limit, which I hoped to get around by
using =AVERAGE (()). In another thread someone referred to this as using
"multiple area ranges."

That seemed to be working fine until about one hour into the tedious process
of selecting cells while holding down ctrl, I get the "too many characters"
notification.

Surely there is some efficient way of averaging more than 30 non-adjacent
cells?? I can't believe that Excel makes it this difficult to do a simple
calculation. Any suggestions? Thanks.