Feature request: Variable substitution

[stertingen]

Is your feature request related to a problem? Please describe.
I would like to set up C/C++ IntelliSense with includes and defines for MEX files for the correct MATLAB installation.
Maybe even the configured compiler for MEX (the one from mex -setup).

Describe the solution you'd like
I would like to use something like ${command:matlab.getMatlabRoot} within settings.json and c_cpp_properties.json.
See also: https://github.com/microsoft/vscode-cmake-tools/blob/main/docs/cmake-settings.md#variable-substitution

Describe alternatives you've considered
Not really, maybe environment variables?
The MATLAB extension could also provide a C/C++ configuration similar to CMake Tools, but i'm not sure how it does that. (https://code.visualstudio.com/docs/cpp/configure-intellisense)

Additional context
Again, CMake Tools provides really convenient variable substitution features.