On fly:
Code:
=IF(ISNA(MATCH(LEFT($B$4,4),{1016,1021,1022},0)),"B","A")
Edit! Are you sure about using OR() in your formula? Or() returns True when at least one expression in it returns True - in your case to get False LEFT($B$4,4) must be equal to 1016, to 1021 and to 2022 concurrently!