MSFS2020 and FSUIPC7 - Setting a Variable by LUA Script

[a350pilot 2]

Hello,

hope, that somebody could help me out with my Problem.
I want to set a Light Potentiometer in the A32NX from FBW.

So, i identified this indexed Variable as an Example.
Glareshield Integral Lights            LIGHT POTENTIOMETER:84       0..100R/WMSFS VAR

Could someone please give a Hint, how to code this in a LUA Script?
I tried it this Way ipc.writeLvar(("L:LIGHT_POTENTIOMETER_SET:84"), 100)
But it didn't work. Any Help is highly appreciated

Thanks a Lot in Advance.
Joachim

Edited January 10, 2022 by a350pilot