DFM - Direct Manual Focus Peaking Help ...

Most of the time I have my NEX-5R focus settings to DMF. I'm trying to figure it out if it's even possible to fix the zooming feature to fine adjust the focus I want without having to keep the shutter button half way pressed (or any equivalent solution that helps the process)? The reason I wanna know this, is because sometimes the camera auto focus in an object I don't want to focus on, and turning the focus ring (to activate the manual focus adjust) + moving the zoom image around (either with the on screen arrows or using the circular controls to find the picture main object) + adjusting the peaking focus all with the shutter button half the way pressed is very tricky. I often accidentally release the shutter button and need to restart the process all over again, which SUCKS BIG TIME..

Hope someone can help me here ...