Bounty: create D6 preprocess function

Greetings,

After realizing I don't quite understand the preprocess function for D6 I think I'll need help with this.

I basically need this issue resolved:

http://drupal.org/node/342965

So that with the Slider module, ever LI has its own unique class, not just the first and last.

$50 bounty to whomever can provide the snippet needed to accomplish this.

Thanks,

jimi089