Patrick Molloy wrote:

syntax for format is wrong

"=RC[4] / (" + Format(100 - dblNewProdSaving ,"0.00" ) + " / 100)"

That's what I thought too, but I get the same error. By the way, am I right that VBA always expects "." as decimal sign, regardless of my regional settings?

but i suggest

with rangetarget
.formulaR1C1 = "=RC[4] / (" & (100 - dblNewProdSaving ) & ")"
.NumberFormat ="0.00%"
end with

Sorry to say, but this also produces the same error: "Application defined or object defined error" (duh!). Also tried putting NumberFormat first.

As an alternative, I tried changing the format of the cell from which I take dblNewProdSaving:

dblNewProdSaving = Format(ws.Cells(5, 4), "0.00%")

But this results in a "type mismatch" error. Ideally, I'd like to change it behind the scenes, to avoid confusing the user.

Gustaf