With brake lever pivot point I'm referring to the part that the brake lever hinges on/around. I'm quite curious to how you manage to adjust that one short of doing some serious machining on the lever and its housing. You must be thinking about some other part of the assembly.

Look at the pic, The lever pivots around the stubby axle just below and to the right of the return spring. Turning the adjustment screw will effectively change the amount of leverage and stroke that the brake lever has.
The fact that there is an oblong bit between where the cable hooks on and where the adjustment is carried out doesn't change a thing, it's just acting as a linkage and doesn't influence the basic issue of the way the leverage changes as the adjustment is turned up or down.