SQL & PL/SQL

Hi guys,

Basically I need to use REGEXP_REPLACE in order to remove from a string certain oracle code pricislly those which are used on RAISE_APPLICATION_ERROR from 20000 to 20999. We have an application here that handles those exceptions and each exception append each other so inside them we can find those ORA-20001: Some error. ]

So I was wondering if I can achieve that by using REGEXP_REPLACE. So which regexp I could use so that I can remove those oracode only!

Thanks!