I would normally say:
which will do the equivalent of pressing the end key then the down cursor key while on 420 however it only works if there is more than one entry in the list at 420 otherwise you get the bottom.
There may be smarter ways of doing it but how about
If range("A421") <> "" Then
Which will go to the bottom of the column in A if there is something in A421 otherwise it will go to a421 ?