Stronger DOF

Hello I wonder if there is a way to manual override focus. In the attachment there is an example of my problem. I want to have the armrest focused and the background and the small table out of focus. I used a 200 lens with F 1.0. but that is the best result. The background is 5,6 meters far from the sofa so should be much more blurried.
I can push the F to the impossible 0.1 and play with iso and exposure to correct the excessive brightness and that partially solve the problem. Or I can use a 500 or 1000 lens, but that is impratical where the scene is big and there are a multiple objects or walls. I didn’t see much about clipping planes in unreal. Also I’d like to have my object not completely deformed from the huge zoom. The ideal solution should be to have focus parameters indipendent to real camera factors, so I can put out of focus whatever I want without becoming crazy setting the camera or finding other solution to create the shot I want.