Long nested IF statement creates runtime error 1004 in Excel VBA

Question

I have a formula that works perfectly well in a spreadsheet, but when I try to automate the creation of the formula using VBA, I get the 1004 run time error.

I have a 3 stage process, each with a start and finish date (so 6 separate date columns). This formula looks at the series dates and calculates the time lost between each stage using the NETWORKDAYS function.

I thought the simple way to overcome this problem was to record a macro of me pasting this formula into a cell, which would generate the required VBA code that I could then adapt, but even using this method causes the 1004 error.

I'm wondering whether it's the length of the formula that's the problem? I've tried replacing the double quotation marks with & Chr(34) & Chr(34) & and I've tried assigning the formula to a variable. I can get it to work if I add it as text using .value instead of .formulaR1C1, or if I add an apostrophe to the start of the formula string. It appears to be the fact that its a formula that causes the problem. Any help is greatly appreciated.

The formula from the cell in the spreadsheet:

=IF(AND(I2="",J2="",K2="",L2=""),"",IF(AND(G2="",H2="",K2="",L2=""),"",IF(AND(G2="",H2="",I2="",J2=""),"",IF(AND(H2<>"",I2<>"",J2<>"",K2<>""),IF(NETWORKDAYS(H2,I2)-2+NETWORKDAYS(J2,K2)-2<1,"",NETWORKDAYS(H2,I2)-2+NETWORKDAYS(J2,K2)-2),IF(AND(H2<>"",I2<>""),IF(NETWORKDAYS(H2,I2)-2<1,"",NETWORKDAYS(H2,I2)-2),IF(AND(H2<>"",K2<>""),IF(NETWORKDAYS(H2,K2)-2<1,"",NETWORKDAYS(H2,K2)-2),IF(AND(J2<>"",K2<>""),IF(NETWORKDAYS(J2,K2)-2<1,"",NETWORKDAYS(J2,K2)-2),"")))))))

The code that the macro records when I enter the formula into the cell:

ActiveCell.FormulaR1C1 = _
        "=IF(AND(RC[-10]="""",RC[-9]="""",RC[-8]="""",RC[-7]=""""),"""",IF(AND(RC[-12]="""",RC[-11]="""",RC[-8]="""",RC[-7]=""""),"""",IF(AND(RC[-12]="""",RC[-11]="""",RC[-10]="""",RC[-9]=""""),"""",IF(AND(RC[-11]<>"""",RC[-10]<>"""",RC[-9]<>"""",RC[-8]<>""""),IF(NETWORKDAYS(RC[-11],RC[-10])-2+NETWORKDAYS(RC[-9],RC[-8])-2<1,"""",NETWORKDAYS(RC[-11],RC[-10])-2+NETWORKDAYS(RC[" & _
        "8])-2),IF(AND(RC[-11]<>"""",RC[-10]<>""""),IF(NETWORKDAYS(RC[-11],RC[-10])-2<1,"""",NETWORKDAYS(RC[-11],RC[-10])-2),IF(AND(RC[-11]<>"""",RC[-8]<>""""),IF(NETWORKDAYS(RC[-11],RC[-8])-2<1,"""",NETWORKDAYS(RC[-11],RC[-8])-2),IF(AND(RC[-9]<>"""",RC[-8]<>""""),IF(NETWORKDAYS(RC[-9],RC[-8])-2<1,"""",NETWORKDAYS(RC[-9],RC[-8])-2),"""")))))))"

Answer 1

Consider:

Sub EvilFormula()
    Dim st As String, DQ As String
    DQ = Chr(34) & Chr(34)
    st = "=IF(AND(I2=~,J2=~,K2=~,L2=~),~,IF(AND(G2=~,H2=~,K2=~,L2=~),~,IF(AND(G2=~,H2=~,I2=~,J2=~),~,IF(AND(H2<>~,I2<>~,J2<>~,K2<>~),IF(NETWORKDAYS(H2,I2)-2+NETWORKDAYS(J2,K2)-2<1,~,NETWORKDAYS(H2,I2)-2+NETWORKDAYS(J2,K2)-2),IF(AND(H2<>~,I2<>~),IF(NETWORKDAYS(H2,I2)-2<1,~,NETWORKDAYS(H2,I2)-2),IF(AND(H2<>~,K2<>~),IF(NETWORKDAYS(H2,K2)-2<1,~,NETWORKDAYS(H2,K2)-2),IF(AND(J2<>~,K2<>~),IF(NETWORKDAYS(J2,K2)-2<1,~,NETWORKDAYS(J2,K2)-2),~)))))))"
    st = Replace(st, "~", DQ)
    ActiveCell.Formula = st
End Sub

Here we first construct a String that represents the formula, but uses tildas in place of pairs of double-quotes. We replace the tildas and deposit the formula.

I use this to avoid migraine headaches.