Creating an iPart Issue

So I have a iPart to make sprockets at different pitches but cannot figure out for the life of me how to create a Tap hole were i can change the thread size from a drop down menu!! I can suppress it and compute the standard 10-24 tap that I created but I want to be able to select from a few different tap sizes during creation. Is there an easy way to do this?

if i remember right the tap hole feature is based on the hole size. My initial thought is you may be able to go from fine to course(10-32 to 10-24) but i dont know about other sizes. Sorry i dont have an exact answer for you though.