Surprisingly it's not an easy thing to do.
I know that hawtness was working on a method of auto dc with relog and it turned out he had to do some fairly decent level of packet blocking and work with assembly. Unless you mean a simple pixel based macro that checks for the dc window, closes it, types a fixed password and relogs then there's no simple way to do this.
Sorry but there's no public bots atm that have auto relog functionality.