I'm not sure if this is "do-able" but would
appreciate some advise.

Worksheet has three columns with
data validation for the user to answer
Yes or no to question posed. I have
been asked to make a small change:
Add to the list for the first column
"Yes to all" along with "Yes" and "No".

So, if user answers "Yes" to all" I want
the next two columns to automatically
default to "Yes" from blank. I tried
using:

=If(E6=AZ2,AZ1)

But I get an error.

AZ1 = Yes
AZ2 = Yes to All
AZ3 = No

E6 is my first cell in my first column.
I was attempting to put the formula in F6.

Can anyone offer some suggestions?