Hello
Many thanks for your help, I have discovered that you can download ported versions of the Unix utilities. I have downloaded them from here:
http://sourceforge.net/projects/unxutils/I have copied those files to C:\Windows\System32 and then using the command just as you wrote it:
module_begin
module_name folder_size
module_type generic_data
module_exec du -h -b -s "C:\Program Files\" | cut -f 1
module_description Folder size
module_end
Enables us to monitor the size of that folder.
Thanks massivly for huge point in the right direction, i think Pandora is now doing everything that we need it to!