Excel formula in Data Range, row members are not static

We have a simple scenario.

We have materials in rowkeyrange.

These are not static. Everyday new materials added.

And we have accounts in colkeyrange.

These are constant.

We are using excel formulas in data ranges.

When new materials come, these formulas don't expand.

is there a way to automate this scenario?

Materials
Acoount1
Account2
Account3 Material1 10 2

=20

Material2 20 3 =60 Material3 5 5 =25 Material4 30 10 =????

Assume that material4 has added. There is a formula in the last column.

Account3= Account1xAccount2

Is there a way to do this?

We wont use dimension formulas.

There is no Expansion in the columns.

There is expansion in the rows.