Question

I have some cells with, for an example, this value:

5*A-2*B-4*C

In other cells I would put the values for A, B and C. I would like to make additional cell that would count the value. So, for an example, if in some cells it is written that the value of A is 2, value of B is 3 and value of C is 1, I would like an additional cell that would calculate and put the value 0 (that’s the result of 5*2-2*3-4*1). Possible variables are A, B and C, but they don’t have to be contained in every cell (e.g., some cell may be just 5*A-3*C).

Is that possible? Does anyone know how to write that function?

P.S. I can’t split manualy values in different cells because there are hundreds of them.

Thanks.

Answer 1

This can be done with the VBA function EVALUTE

simple example:

Function ev(f As Variant, A As Range, B As Range, C As Range) As Variant
    Dim s As String
    s = f
    s = Replace(s, "A", "~A~")
    s = Replace(s, "B", "~B~")
    s = Replace(s, "C", "~C~")

    s = Replace(s, "~A~", A.Address)
    s = Replace(s, "~B~", B.Address)
    s = Replace(s, "~C~", B.Address)

    ev = Evaluate(s)
End Function

eg if your expression is in A2, and the values of A, B, C are in C2:E2

=ev(A2,C2,D2,E2)

returns the calculated value

You would want to use a ParamArray instead of A, B, C the variable values to allow for an arbitrary number of variables.

A slightly more complete version:

Function ev(expr As Variant, VarNames As Range, varValues As Range) As Variant
    Dim s As String
    Dim i As Long

    s = expr
    For i = 1 To VarNames.Columns.Count
        s = Replace(s, VarNames.Cells(1, i), "~" & VarNames.Cells(1, i) & "~")
    Next
    For i = 1 To VarNames.Columns.Count
        s = Replace(s, "~" & VarNames.Cells(1, i) & "~", varValues.Cells(1, i).Address)
    Next

    ev = Evaluate(s)
End Function

Usage:

Same data as above plus variable names in C1:E1

=ev(A2,C1:E1,C2:E2)