Sonoff 4ch for allarm system

[IZ1MIG]

I would need to program a Sonoff 4ch to activate an alarm system via the buttons of a three-button remote control, suitably connected to the clean contacts of the sonoff. By giving the command for one of the three alarm states (Away from Home, Night and Off), the corresponding relay should activate for two seconds to close the remote control contact, but, if the away from home or night alarm is activated, the icon to be homekit should remain active to signal the alarm on, and turn off giving the command off.
Furthermore, from a free GPIO of the sonoff, it should detect the on or off status from a status relay present on the alarm control unit, so that it is turned on or off by the homekit even if it is controlled with the key from the control outside the home.

Who can help me?