Collectible Card Game Headquarters

I want to move the cache dir from system partition to other place as the pictures occupied a lots of the limited space.
Now my cache dir is "C:\Users\Andrew\AppData\Local\Forge\Cache"
the user dir can be changed while the cache dir canot
I read the example file it seems the windows syetem could not modify it as the unix

Why can't it? The forge.profile.properties file has a line for Cache and a line for User.

My Profile looks like:

userDir=C:/Users/Sol/AppData/Roaming/Forge
cacheDir=C:/Users/Sol/AppData/Roaming/Forge/Cache

but it easily could be D:/Forge/ and D:/Forge/Cache