cell references help needed

Hello
I am having a problem with the syntax of cell references in two places in an Xcel program.
Someone may be able to see the problem with the code very quickly.
Appreciate any code change suggestions.

1) I am trying to write general code that will handle any number of components (=M).

Can you see what is wrong with this line of code:

ActiveCell.Offset(0, 1 + i) = "=Input!R[i]C[-30 - i]"

as shown below?

All the ‘commented out code is what the for loops are meant to do and is code that works when I run it specifically for M = 5

Case 5
' headings
    Range("AF8").Select
         
    ActiveCell.FormulaR1C1 = "=Input!R[-1]C[-29]"
    ActiveCell.Offset(0, -1) = "Animal"
    ActiveCell.Offset(0, 1) = "=Input!RC[-30]"
    
    For i = 1 To M - 2
   ActiveCell.Offset(0, 1 + i) = "=Input!R[i]C[-30 - i]"  
Next i
     
    'ActiveCell.Offset(0, 3) = "=Input!R[2]C[-32]"
    'ActiveCell.Offset(0, 4) = "=Input!R[3]C[-33]"
    'ActiveCell.Offset(0, 5) = "=Input!R[4]C[-34]"
    
    ActiveCell.Offset(0, 15) = "Total"
    ActiveCell.Offset(0, 16) = "=RC[-17]"
    ActiveCell.Offset(0, 17) = "=RC[-17]"
    ActiveCell.Offset(0, 18) = "=RC[-17]"
    
    For i = 1 To M - 2
    ActiveCell.Offset(0, 18 + i) = "=RC[-17]"
    
    'ActiveCell.Offset(0, 20) = "=RC[-17]"
    'ActiveCell.Offset(0, 21) = "=RC[-17]"
    'ActiveCell.Offset(0, 22) = "=RC[-17]"
    Next i
    
    ActiveCell.Offset(0, 23) = "=RC[-17]"
    ActiveCell.Offset(0, 32) = "=RC[-17]"
    ActiveCell.Offset(0, 33) = "=RC[-17]"
    ActiveCell.Offset(0, 34) = "=RC[-17]"
    ActiveCell.Offset(0, 35) = "=RC[-17]"
    
    For i = 1 To M - 2
    ActiveCell.Offset(0, 35 + i) = "=RC[-17]"
    
    'ActiveCell.Offset(0, 37) = "=RC[-17]"
    'ActiveCell.Offset(0, 38) = "=RC[-17]"
    'ActiveCell.Offset(0, 39) = "=RC[-17]"
    Next i
           
    ActiveCell.Offset(0, 49) = "=RC[-17]"
    ActiveCell.Offset(0, 51) = "Digestibility"
    ActiveCell.Offset(0, 52) = "Faecal output (kg)"
        
    'values
    Range("BO9").Offset(0, M - 2).Select
        
    Do While IsEmpty(ActiveCell.Offset(0, -34 - M)) = False
    'CSM kg
        
    ActiveCell.FormulaR1C1 = "=VLOOKUP(RC[-34 - M],CSMlist,5)"
    'total
    ActiveCell.Offset(0, -18 - M) = "=SUM(RC[-15]:RC[-16 + M])"
   
   ' proportions
    ActiveCell.Offset(0, -17 - M) = "=RC[-17]"
    
    For i = 1 To M
    ActiveCell.Offset(0, -16 - i) = "=RC[-17]/RC47"
    Next i
    
    'ActiveCell.Offset(0, -21) = "=RC[-17]/RC47"
    'ActiveCell.Offset(0, -20) = "=RC[-17]/RC47"
         
    ActiveCell.Offset(0, -1 - M) = "=SUM(RC[-15]:RC[-1])"
    ActiveCell.Offset(0, -M) = "=RC[-17]"
    
    'kg
    For i = 1 To M - 1
    ActiveCell.Offset(0, i - M) = "=RC[-17]*RC[65+M]/RC[48+M]"
    Next i
   
    'ActiveCell.Offset(0, -4) = "=RC[-17]*RC71/RC54"
    'ActiveCell.Offset(0, -3) = "=RC[-17]*RC71/RC54"
    'ActiveCell.Offset(0, -2) = "=RC[-17]*RC71/RC54"
    'ActiveCell.Offset(0, -1) = "=RC[-17]*RC71/RC54"
    
    ActiveCell.Offset(0, 16 - M) = "=SUM(RC[-15]:RC[-1])"
    
        'digest
    ActiveCell.Offset(0, 18 - M) = "=(RC[-36]-1)/RC[-36]"
    ActiveCell.Offset(0, 19 - M) = "=RC[-3]*(1-RC[-1])"
    ActiveCell.Offset(1, 0).Select
    Loop
    
    
 ' hide unused columns
    Range(R8C32 + M, R8C44).Select
    Selection.EntireColumn.Hidden = True
    Range(R8C49 + M, R8C63).Select
    Selection.EntireColumn.Hidden = True
    Range(R8C66 + M, R8C80).Select
    Selection.EntireColumn.Hidden = True

2) I cannot get

Pred = Pred + Solver!RC" & 31 + i & " * "Input!R" & 6 + i & "C[2]"

to work below.

Again the ‘commented out code that it is designed to replace, works

Case 5
' 5 plant components
    
   Range("B9").Select
        
    Do While IsEmpty(ActiveCell.Offset(0, -1)) = False
    
    If n = 4 Then
    
    Pred = 0

For i = 1 To M

Pred = Pred + Solver!RC" & 31 + i & " * "Input!R" & 6 + i & "C[2]"
Next i
    
    For j = 1 To 13
    
'    ActiveCell.FormulaR1C1 = _
        "=((Input!R[22]C[2]/Input!R24C[2]-(Solver!RC32*Input!R7C[2]+Solver!RC33*Input!R8C[2]+Solver!RC34*Input!R9C[2]+Solver!RC35*Input!R10C[2]+Solver!RC36*Input!R11C[2]))^2)"
     
 '   ActiveCell.Offset(0, j) = _
        "=((Input!R[22]C[2]/Input!R24C[2]-(Solver!RC32*Input!R7C[2]+Solver!RC33*Input!R8C[2]+Solver!RC34*Input!R9C[2]+Solver!RC35*Input!R10C[2]+Solver!RC36*Input!R11C[2]))^2)"
    
  '  Next j
    
    ActiveCell.FormulaR1C1 = _
        "=(1*(Input!R[22]C[2]/Input!R24C[2]-Pred))^2)"
    
    ActiveCell.Offset(0, j) = _
        "=(1*(Input!R[22]C[2]/Input!R24C[2]-Pred))^2)"
    
    Next j

I’ve tried different coding w/o success.