variable to store multiple values

You could use MATCH:

Do
    ActiveCell.FormulaR1C1 = _
        "=IF(ISNUMBER(MATCH(RC[-2],Map!R2C3:R7C3,0)),0.03125,1)"
    ActiveCell.Offset(1, 0).Select
    Loop Until IsEmpty(ActiveCell.Offset(0, -2))