To accomplish this, I set up an L(A) detent near the 100% end of the detent frame and calibrated it. I then set the Curve % to 100% so that the throttle will be at 100% when I reach the detent, and stay at 100% as I push through it and beyond. Then I set up a > (greater than) event to trigger a button when I pass the detent. The button will be bound to the WEP function in DCS.
When I move the throttle from full back to the detent the "red" lines on the detent configuration box that show logical output do indeed move from zero to 100 as expected. However as soon as I reach the detent they drop back to the "raw" location, ignoring the curve scaling. See picture below that shows the red lines matching the black arrows at the lower edge of the detent, when the red should be at 100% here. The red line jumps back to 100% as soon as I push past the detent.
This problem only occurs if I set the curve to 100%. If I set it slightly lower (at 98%, for example), everything works as expected. This makes me suspect that the problem is caused by an edge-case programming bug in the firmware.
I also tried this with a W detent. The problem still occurs, except that the red line jumps from 100% to the center of the detent range when I reach the lower edge.
