While I’m not able to puzzle out a way to 3D model this in Carbide Create, it can be cut in Carbide Create — just the stock size as a square and make a series of rectangles and triangles:
Then dupe it as two files and model the top/bottom and left/right slopes in each and cut them:
To do the cutting, select the triangles which one wishes to cut out and offset by the radius of the endmill which will be used:
Cutting the two attached files sequentially should yield the desired cut:
26_875_19_875_doorpanel_2 of 2.c2d (98.2 KB)
26_875_19_875_doorpanel_1 of 2.c2d (96.3 KB)