Pull pot for all 3 pickups on a 5-way switch?

I want to put a pull-pot on my 3 pickup Tele so that I can have the neck and bridge pickup together or all 3 pickups at once. I don't want a Brent Mason set-up with a 3-way switch and blender, I want to keep the 5 way switch that's already in the guitar and don't want have to route for a larger cavity to house the third pot in the Mason set-up.

Any help greatly appreciated!

Copy the push pull portion of this diagram:

http://cdn.seymourduncan.com/images/support/schematics/switch_f_bp.jpg

Thanks Garrett!