Adding Tapped Holes

I'm sure somebody has covered this before but I don't remember how to add "odd"
sized tapped holes to the hole wizard. For
example, I want to add a 1 1/8"-18 hole to the wizard and I have the related
data but can't find a file where the "standard"
data resides.
Could anyone provide the file name and/or the method to add these odd sized
holes.
SWX 2003/P4-2.4 GHz/1GB/Gforce
R. Wink