if it's just renaming you're after then you can just rename it after its all been rendered

i found a few links to programs that can mass rename stuff (googled "batch file rename", i was actually...

wait, so you're hard-coding it all in?
dude... that's gonna be a bitch.....
I'm not too too confident in MEL scripting but my solution to this problem is to write a program to renamed them all...

does it have to start at 00000?
why not batch render from 00001 to 99999

you can change the output file names in the render settings