Flexible user parameters Problem / Windows

[spiderp2351]

Why is this flexible user parameter Active

folder_size[E:/smartform/Rechenzentrum/pc001/projekte]

and this flexible user parameter "Not supported"

folder_size[E:/smartform/Rechenzentrum/pc001/smartform_close]
folder_size[E:/smartform/Rechenzentrum]

On Client Site:
UserParameter=folder_size[*],perl c:\Programme\utils\du.pl $1

Output from du.pl E:/smartform/Rechenzentrum/pc001/projekte like this:
254654555


http://www.zabbix.com/documentation/...ser_parameters
there only this infomation:

Unless UnsafeUserParameters agent daemon configuration option is enabled, it is not allowed to pass flexible parameters containing these symbols: \ ' ” ` * ? [ ] { } ~ $ ! & ; ( ) < > | # @

Thanks for Help
Markus