How to remap mouse related shortcuts in editor

Hello,

I am having very hard time figuring out how to remap mouse related shortcuts in UE4. I am a 3D artist, and coming from 3D package, I am used to 3D software style navigation, therefore I mostly use Alt+mouse buttons or RMB+WASD to navigate, but I never use holding down LBM, MMB or RMB to navigate. The LMB hold-down is a very luxurious top level shortcut that is being wasted on something as old as almost 20 years old legacy navigation scheme from unreal engine 1, therefore I would like to map it for something meaningful, like marquee select, because I need to select clusters of objects all the time.

I’ve searched all over the keyboard shortcuts tab of editor preferences, but could not find a way to change the keyboard+mouse or mouse only mappings. Any help will be much appreciated.

Thank you