Using .ctb files with batch plot utility

I have a question for all the AutoCAD 2000i users. I have been using AutoCAD
LT2000 and am used to the .ctb file for plot pen propertites. I have now
started using the full blown AutoCAD 2000i and use the same .ctb file for
plotting. I am trying to learn the batch plot utility now and can't seem
to use my .ctb file. It seems to want a .pc3 file.I have set this up but
cannot associate my .ctb file to the .pc3 file. Is there a way to use my
ctb file with batch plot or assign this .ctb file to my .pc3 file? Thanks
for the suggestions.
Randy