how look up non-continguous items?

[Ian Elliott]

Thanks for any help. I am trying to use OFFSET to look up every other 3rd
item from a vector, but I don't think it can do that. Are there other
functions that can?
For example,
A1 has 5.4
A2 4.3
A3 7.6
A4 9.9
A5 11
....
A120 12.1
and I want to look up A1, A4, A7,...,A120 (I think the last one is A120).
and multiply by another vector. I would do by hand, but there are about 120
total items.
Any help much appreciated.
thanks

 

[T. Valko]

Need more info.

and multiply by another vector.

What other vector?

And what is the result you expect?

Do you want the total sum of this multiplication (the sum of products)?

Referencing every nth cell in a range is not a problem but what do you want
to do with them once we "find" them?