HI all

I want to insert IFERROR. IFERROR cell will blank ""

Into this bit of the code 
 .Formula = "=IF(B6<>"""",B6,INDEX(H$6:H$355,ROWS(M$6:M6)-COUNTA(B$6:B$355)))&"""""
I tried but gives me an syntax error! many thanks in advance


Private Sub Worksheet_Change(ByVal Target As Range)

Dim oldcell As Variant

Dim StartTime As Double
Dim SecondsElapsed As Double
  StartTime = Timer
  
oldcell = ActiveCell.Address

If Target.Column > 1 And Target.Column < 7 Or Target.Column > 7 And Target.Column < 12 Then

    With Range("M6:Q355")
    'IF ERROR FORMULAE NEEDS TO BE ADDED!
    
    .Formula = "=IF(B6<>"""",B6,INDEX(H$6:H$355,ROWS(M$6:M6)-COUNTA(B$6:B$355)))&"""""
    .Value = .Value
End With

Range("O6:O355").NumberFormat = "mmm-yy"
Range("Q6:Q355").NumberFormat = "mmm-yy"
    
    'Determine how many seconds code took to run
  SecondsElapsed = Round(Timer - StartTime, 2)

'Notify user in seconds
  MsgBox "This code ran successfully in " & SecondsElapsed & " seconds", vbInformation

End If


End Sub