VBA Autofill or Formula Range

[Littlemalky]

I'm struggling with this, I have a weird range I'm working with to insert a formula, and I'm trying to autofill it down, or maybe there is a way to just set the range in the formula to filldown. Basically, I need the formula to filldown from the 5th row to the 27th row on the sheet. The column part is dynamic, and the formula is a VLOOKUP looking at Column A. Here is my formula, but I'm struggling to fill it down to the 27th row.

Workbooks("" & Format(DateSerial(Year(Date), (Month(Date) - 1), Day(Date)), "yyyy.mm") & " summary.xlsx").Worksheets("Domestic").Range("A5").End(xlToRight).Offset(0, 1).Formula = _
        "=IFERROR(VLOOKUP(A:A,'[" & Format(DateSerial(Year(Date), (Month(Date) - 1), Day(Date)), "mm-yyyy") & " Domestic.xlsx]Summary'!$A:$D,4,0),0)"