FSRM - Total space used in multiple folders

[Pyroman]

Heya,

 

Our finance department wants to know how much space a particular department is using to be able to charge them for backup usage. They have folders in (GENERALSHARE\DEPT1) (STAFFSHARE\DEPT1) (STAFFHOMES\USER1 to USER15) how can i get the total size for all folders in a report in FSRM instead of having to use windirstat on individual folders and adding them all up?