Oracle 9i - I realize there is a plug-in in 11g that can check for multiple instances of a character

 but how would I do this in 9i?  I have a requirement to check that the password has no more than 3 consecutive characters of the same character type in the password, for instance no more than 3 numbers together in a password -Hello1234 should be rejected.

The verify_password function goes through each character set array to ensure 1 of each character, but how do I tell it to check that there are no more than 3 from the same array in the password?

Thanks.

Noemi