renaming html output files from FrameMaker

I am trying to replace split file names from long FrameMaker chapter documents. Regardless of the .prj file and mif2go.ini content I still get the same aa*.htm files. I have one chapter that does export to the file naming convention set up in the .ini and .prj files but am unable to replicate it in any other chapter. I've also poured through 18.4.1.2 in the help file, but can't seem to make heads or tails of it with respect to my documents. I'm looking for a file naming sequence of something like P1_v1_1.htm which increments to P1_v1_1.htm, P1_v1_2.htm, P1_v1_3.htm etc.

Appreciate the help on this.