I am not sure if you could directly do so through DBI but you could certainly use sqlplus and then automate the password generation and changing via Expect. Granted this is not a pure perl solution but it works.
Comment on Re: How to change expired database password via DBI?
There are a couple problems with that suggestion; One, sqlplus is Oracle, not SQL Server; two, many of our users do not have TOAD or Query Analyzer on their computers.