Multi-out VST - Directing to specific channels

I want to upscale a stereo signal to 3 channel stereo with
SurCode for Dolby Pro Logic II VST plug-in

How can I redirect the channels to specific channel outputs?

I have tried with FL Studio, but I am not able to select other than output 1.

I am using ASIO4ALL and should have two channels on this test machine.

I tried to install Voicemeeter but now I am not able to
select any outputs.