SUBTRACTING

[Kelly]

I know excel can subtract columns relative to each other if they go in
order (a1, b1, c1...) minus some variable.
Can excel subtract every third column (a1, d1, g1) minus some
variable??

Is this possible?
Can I write a simple formula, or would it have to be done in a macro?

 

[JE McGimpsey]

I know excel can subtract columns relative to each other if they go in
order (a1, b1, c1...) minus some variable.
Can excel subtract every third column (a1, d1, g1) minus some
variable??

Is this possible?
Can I write a simple formula, or would it have to be done in a macro?

I'm nopt quite sure what you mean by subtracting columns relative to
each other.

Could you explain a bit further?