Using environment variables in the path to assets to make external assets synced between different operating systems

I know assets located outside the graph folder can be embedded like ![xxx.pdf](file://absolute_path/to/xxx.pdf).

My question is, if xxx.pdf is synced between OSs with cloud storage like OneDrive, it may be located at different paths in different OSs, so the absolute path will not work. Can environment variables be used like ![xxx.pdf](file://$OneDrive/relative_path_to/xxx.pdf), so that in any different OSs the file can be found wherever the $OneDrive env variable is defined?