Is it possible to put an environment variable "as value" for CustomToolsPath in the femap.ini or it needs to be the full path? It be easier to share the company APIs.
Unfortunately that is currently not possible, however you might be able to approach this another way. Depending on your network configuration and what you need to do, it might be possible to have everyone use the "Map Network Drive..." capability in Windows to make a central API directory look like a drive letter... say "X:\". Then you would just specify "X:" as the CustomToolsPath.