I don't mean to shoot down your methodology, but I have a problem with hacking in changes if there's a way to do them up front. Could you use a script to populate winnt.sif? Is the format of the .sif file ASCII? Like I said, this SE just passed one parameter to a batch file and stared at the sky.
Not sure about the comment part, but that would be easy to do afterwards.
_________________________
Give a man a fish and he will be back for more. Slap him with a fish and he will go away forever.