Range("A1").formula="=IFERROR(VLOOKUP(A2,[Book1.xlsx]Sheet1!$A$2:$C$8,3,FALSE), "")"
Something = Application.WorksheetFunction.VLookup(arg1, arg2, arg3[, arg4])
Something = Application.WorksheetFunction.VLookup(arg1, arg2, arg3[, arg4])
Something = Application.VLookup(arg1, arg2, arg3[, arg4])