[PERDITION-USERS] Script Maps

Hello, Is there a map module for perdition that gets the necessary information it needs by using a script ? I was thinking something like the script runs in a constant while loop reading each line from STDIN and returns the remote server information to STDOUT. This is basically how authentication programs are used with the squid web proxy. I'm asking this because I am looking into a setup that runs multiple dovecot servers which all point back to the same location by use of networked file systems. Everything is working fine apart from a small problem that is related to users logging into two different servers at the same time. So although I need to make sure users are always connected to the same server this doesn't have to always be the same server but just the same server within a set amount of time from when the users logs in and I could quite easily set this up if perdition supported scripts as its backend. I'm sure this will open up other possibilities such as using database backends that perdition doesn't have a module for. Cheers, Matt.