Add and Remove from PATH

When I start up the platform, I would like a setting to allow me to PREpend portable app directories to my PATH environment variable. When I shutdown the platform, I would like those items removed from the altered PATH.

The purpose of this is to put portableapps in the front of the line for CLI. For example, there might be an older version of a program installed to the system I am using. I want my newer portableapp version to be found first on a command line prompt.