Shear(?) matrix projection along Z (depth) axis
I belive what you are looking for is a scale Matrix, or actually it will end upp with as a shear matrix for you.
Usually they look like this
Sx  0   0   0
0   Sy  0   0
0   0  Sz   0
0   0  0    1

If you have no scaling, Sx, Sy, Sz represent the scaling in corresponding dimension.
So put the to 1 for no scaling.
But now you want to scale the height depending on the z value. So we want to modify it abit. If you would put Sx, Sy, Sz to the value one. And the put a higher value than one on Syz, then it would scale the height (Y), the futher away you are.
Sx  0    0   0
0   Sy  Syz  0
0   0   Sz   0
0   0   0    1