Does the program use DBD::ODBC or Win32::ODBC - if the former it will be as simple as changing the 'connect string' , if the latter you will almost certainly have to rewrite the whole thing. Having said that if you have libodbc on your Unix machine and your database is ODBC compatible (Informix, Oracle and PostgresSQL definitely are but there are probably others) then DBD::ODBC may work but it is probably not worth the extra overhead if there is a DBI driver for your database.

/J\