creating report on local my documents size

Hi,

I am trying to figure out if it is possible to create a report which reports the size of the my documents folder on the local harddrive.

Or all folder sizes in the users folder on windows 7.

The report i found (Local user Account information) gives me all the users that logged on to the computer but the profile size is the same for every profile. Besides the fact that the profile folder is given as C:\Windows

Or is there another way to create a custom inventory rule to collect this information.

Jasper