How to set Target.WindowsPlatform.bUpdatedCPPMacro?

Hello,
I’m trying to use a third party library inside ue5. For it to compile, I need to add the “Zc__cplusplus” option to the compiler.
While going through a file named “VCToolChain.cs” I found out that, the needed option will be included if the variable “Target.WindowsPlatform.bUpdatedCPPMacro” is set to true.

So my question is where and when is this variable set?
Can I set it in some non hacky way?