Can you set a cell to a formula in VBA with relative values

Dim startCell As Range, endCell As Range, formulaCell As Range
Set startCell = ReferencedWorksheet.Cells(7, LastCol+2 )
Set endCell = ReferencedWorksheet.Cells(LastRow, LastCol+2 )
Set formulaCell = ReferencedWorksheet.Cells(LastRow + 1, LastCol + 2)
formulaCell.Formula = "=SUM(" & startCell.Address & ":" & endCell.Address & ")"