You can use standard Windows environment variables and system variables in CCleaner's INI files.
An environment or system variable is a shortcut that points to a specific folder.
For example, %APPDATA% points to where the current user's application data is stored. If the user is running XP, logged in as Administrator and Windows has been installed to the C: drive, %APPDATA% would point to C:\Documents and Settings\Administrator\Application Data.
This is very convenient if you plan to share your INI files or use them on multiple computers, since you don't have to know in advance all the custom Windows folder settings that might exist.
System variables in Windows:
Parameters are basic environment variables in Microsoft Windows.
Managing Environment Variables & System Variables
You must be an administrator to modify a system environment variable. System environment variables are defined by Windows and apply to all computer users. Changes to the system environment are written to the registry, and usually require a restart to become effective.
User Variables for User Name
Any user can add, modify, or remove a user environment variable. These variables are established by Windows XP Setup, by some programs, and by users. The changes are written to the registry, and are usually effective immediately. However, after a change to user environment variables is made, any open software programs should be restarted to force them to read the new registry values. The common reason to add variables is to provide data that is required for variables that you want to use in scripts.
To view or change environment variables: