Checking if a user is logged in

A nightly process requires us to make sure a specific account is logged on, here is the Nagios command to check if a user is logged on.

$USER1$/check_nrpe -H $HOSTADDRESS$ -p 5666 -n -c CheckWMI 
   -a "Query=Select Antecedent from Win32_LoggedOnUser" MinCrit=0 +filter-string:Antecedent=substr:$ARG1$