I download a new spreadsheet everyday, this spreadsheet will have several new
rows everytime. I run a macro

What I need is for this lookup to automatically find the last row in the
table array

Range("H2").Select
ActiveCell.FormulaR1C1 = _
"=VLOOKUP(RC[8],'[Cell Refs Update Macro
V3.xls]Lookup'!R2C1:R1770C5,3,FALSE)"
Selection.AutoFill Destination:=Range("H2:H" & lastrow)

Can anybody help me?