Formula problem, get and sort numbers between two values

[Michaelice]

Hi!
I have been trying and searching all day for a answer but i can't get it to work.
I got a list of uniqe values like this:

10003
10001
10002
20001
20003
20002
30002
30001
30003

I start the values with different numbers to be able to split them up in differente classes
and I need get one of the classes and sort them in descending order.

I've been trying and almost got it to work with this code.

=MIN(IF($A$1:$A$9>20000,$A$1:$A$9),1)

But I would need something like this so I can get a single class and sort it.

=MIN(IF($A$1:$A$9>20000 AND $A$1:$A$9<30000,$A$1:$A$9),1)

I would be really happy for some help here.
Thanks in advance!