Write Excel formula into cell using VBA - excel

Question

I am trying to overwrite wrong Excel formula.
I copied the formula from the cell into the code and placed double quotes.
Already read that I have to type two times " for getting a " into the formula. I can't tell what is really going on, because of companies compliance but the code should do it.
Imagine there are 180 components with the same 18 function in cells. By deleting some components I lost the reference and instead of writing every formula again, I try to do this with VBA.
Sub nachtrag()
Dim i As Integer
Dim j As Integer
Dim Start As Integer
Start = 4
Dim Bezug As Integer
For i = 0 To 179
Bezug = Worksheets("QK-Daten").Range("R" & ((i * 18) + 18) + Start).Value
For j = 1 To 17
Worksheets("QK-Daten").Range("Z" & j + (i * 18) + Start).Value = "=WENN(R" & Bezug & "="""";"""";SVERWEIS(R" & Bezug & ";'QK-Tabelle'!$B$3:$C$123;2;FALSCH))*(R" & j + (i * 18) + Start & "/R" & Bezug & ")+((N" & j + (i * 18) + Start & "+O" & j + (i * 18) + Start & ")*0,3+(P" & j + (i * 18) + Start & "+Q" & j + (i * 18) + Start & ")*0,1)"
Next j
Worksheets("QK-Daten").Range("z" & ((i * 18) + 18) + Start).Copy
Worksheets("QK-Daten").Range("z" & ((i * 18) + 18) + Start).PasteSpecial Paste:=xlValues
Next i
End Sub

Answer 1

Try writing the formula with placeholders in the string and then use Replace() to substitute the values.
Option Explicit
Sub nachtrag()
Dim ws As Worksheet, cell As Range, s As String
Dim Bezug As Long, Start As Long
Dim i As Long, j As Long, r As Long
' formula
Const F = "=IF(R<bezug>="""";"""";VLOOKUP(R<bezug>;'QK-Tabelle'!$B$3:$C$123;2;FALSE))" & _
"*(R<r>/R<bezug>)+((N<r>+O<r>)*0,3+(P<r>+Q<r>)*0,1)"
Start = 4
Set ws = Worksheets("QK-Daten")
With ws
Set cell = .Range("R" & Start)
For i = 0 To 179
Bezug = cell.Offset(18).Row 'Value
For j = 1 To 17
r = j + (i * 18) + Start
s = Replace(F, "<bezug>", Bezug)
s = Replace(s, "<r>", r)
cell.Offset(j, 8).Formula = s 'Z
Next j
' not sure what this is doing
' .Range("z" & ((i * 18) + 18) + Start).Copy
' .Range("z" & ((i * 18) + 18) + Start).PasteSpecial Paste:=xlValues
cell.Offset(18, 8).Value = cell.Offset(18, 8).Value
' next component
Set cell = cell.Offset(18)
Next i
End With
MsgBox "Done", vbInformation
End Sub