How do I add a drill to PCB that DRC will respect?

I'm using OrCAD PCB Designer version 16.3. I would like to know the BEST way to simply define an unplated drill hole in my board, that doesn't come from a schematic element (using OrCAD Capture 16.3). I also need to make sure the hole is automagically dodged when the router places traces and also that I get a DRC error if I manually route a trace through the hole. Right now, I'm creating a via without copper, and the pad designer complains about it. Then, after I place it, no DRC happens if I run a trace through it. Meanwhile, I have a footprint with a peg hole in it. I'm having similar trouble with that. This stuff ought to be obvious, but it's not. I see no ability to simply add a "drill"... Thanks in advance for your help