[Help]Transparance

Hey,
im coding some little D3D hook.
But ive tried to change the black background to black transparant (Around 40%)
So ive got this code:
How do i change this to transparant black?

To change the transparency , you would put the first value of 255 which is (A) , also known as Alpha. The Alpha is the opaque.

To make it fully transparent and see through , you would put (A) to 0. To make it not see through at all , you would put the value to 255.

To make it transparent black , i would set (A) to 100.