Download Dell Display Manager from the Dell website: https://www.dell.com/support/kbdoc/de-de/000060112/was-ist-dell-display-manager
References from the Dell Forum:
Executing a ddm command has a delay of approx. 2 second.
; The path to ddm.exe
ddm_exe = "C:\Program Files\Dell\Dell Display Manager 2\DDM.exe"
; Right shift + volume Up = Monitor volume up by 5
>+Volume_Up::Run, %ddm_exe% /IncreaseControl 62 5
; Right shift + volume Down = Monitor volume down by 5
>+Volume_Down::Run, %ddm_exe% /DecreaseControl 62 5
; Right shift + mute = Monitor volume zero
>+Volume_Mute::Run, %ddm_exe% /WriteControl 62 0