Need Custom Passfilt.dll instructions

After a fruitless search, I turn to you my peers for this one.

I wanted to create a custom Passfilt.dll. I know how to install and use the one shipped. I am looking for the instructions on how to create a custom dll.

I know the instructions are on the nt4sp2 cd.
But I am unable to find it anywhere in my vast msdn collection or online.

The msdn talks in loops and all of the platform sdks I found were of no help.

If someone can find me the instructions I would be most appreciative.