Doesnt work

I have installed this on a test server under NSclient++scripts. As documented in the notes it fails with “ExternalCommands: failed to create process (check_disk_iostat_vbs): 2 The system cannot find the file specified”. If I include in the [External Scripts] section and give the full path to the script I get a Class not Defined: ‘NagiosPlugin’ which suggests there is a wrapper script missing where the classes get defined. Please help.