As long as your range starts in an "odd" column (A, C, E, etc.), and as long
as every cell in the range is filled in with a value (0 or a number, not
empty), this formula should do what you want
=SUMPRODUCT((MOD(COLUMN(A1

1),2)=1)*(A1

1<>0))
where the range starts in Column A as you requested. If, by the way, you
ever want to do this and your range will start in an "even" column (B, D, F,
etc.), then just change the =1 to =0. The above formula ends in column D,
but you can expand that to whatever ending column you want... it is only the
beginning column for the range that must be accounted for.
Rick