Not sure I understand the part I bolted. I assume you're using an old spoke as a reference so that all the nipples will be tightened the same way.
Elsewhere, someone used a similar trick simply to avoid losing the nipple inside the double-walled rim.
I realize the explanation is a bit confusing. Essentially I made a nipple driver out of an old spoke and nipple on the same lines as the bicycle research nipple driver called out be feitsbob. I have the park version, maybe I'm too oc, but I had a hard time getting comfortable using it. I'm going to attach pictures this time. I screw the new nipple until the two spokes touch, i.e. I can't screw it anymore, silver in the photos. Using the homemade driver I'm able to get all of the nipples set pretty evenly before I start tensioning the wheel.