project geometry

... or whatever it's called in SolidWorks... (it's really hard to get help from the help file if you don't know what the feature is called...)  I'm trying to put a bolt hole pattern in the end of a boss, and I need help.  I've extruded a cut into the boss to represent the machining of the face, then I hit Hole Wizard to make the hole, but I need to dimension it from the center of the boss, and I can't get SW to let me project the workplanes in the boss part.  I made a couple work planes in the assembly by offsetting the ones in the part by 0", but it won't let me project them either.  It will let me project the origin of the part, but then it puts a hole there, too... How do I do this?

SolidworksParts And Features