I think a while back there was an issue with not being able to use system variables?

By that I mean:

Windows XP Workstation has a variable (if you were to type: SET in a command prompt you'd see a variable with some value).

For example, we set a variable in the login script:
zcmsource = \\server\volume

I wish to use said variable in ZCM bundles. The docs don't really state if you can use a ZCM variable to reference a system variable

I thought something like:
${source} = zcmsource

would work, but apparently not

The docs aren't totally clear and in TP1 for ZCM 11, the online help has references to items that aren't even on the page that you selected the help for.