You could list your codes somewhere - let's assume column M with "01"
in M1, "02" in M2 etc. Then in N1 you could apply this array* formula:

=MIN(IF(Code=M1,Dates,40000))

* As this is an array formula, once you have typed it in (or
subsequently edit it) you must use CTRL-SHIFT-ENTER instead of just
ENTER. If you do this correctly then Excel will wrap curly braces { }
around the formula - you must not type these yourself.

You can copy the formula down column N for as many codes as you have in
column M.

Hope this helps.

Pete