What you are asking is standard stuff in Excel.

As you think, a cell, say C2 can be set to

=A2+B2

and that can be copied down as far as you want.

Tests can be added,

=IF(A"<"",A2+B2,"No data in column A")

or even more complex

=IF(AND(A2<"",B2<""),A2+B2,"Invalid data")

It can get much, much more complex than that. Most requirements can be met
with functions, but if not, there is always VBA to extend it even further.

--
HTH

Bob Phillips

(replace somewhere in email address with googlemail if mailing direct)

wrote in message
oups.com...
I've only used excel a few times, and what I've read so far doesn't
tell me if this is possible, tho' I have to assume it is. Is it
possible to
assign a formula to a column, say, and have the entire column be
set to a formula with the values of other columns on a row-by-row
basis? That is, something like Cx=Ax+Bx. And since I want it to
be able to handle odd situations, like the absence of some entries,
to set tests -- like set a variable to some value if the cell has no
entry, or has, say, a letter instead of a number? The sort of thing
I could do in APL? Would this require some sort of additional package
to install in Excel? Or does excel do this by itself?

Thanks!

Mark