First version as a replacement for counter checks with check_nt:
check_nt -p 12489 -v COUNTER -l "\\Process(monitoring-agent)\\Private Bytes","Memory Usage (Bytes): ","Bytes" -w 39845888 -c 42991616
./monitoring-agent-client-check-nt-replacement -host HOSTNAME -cacert cacert.pem -certificate cert.cert -key key.key -username USERNAME -password PASSWORD -counter "\\Process(monitoring-agent)\\Private Bytes" -label "Memory Usage (Bytes): " -unit "Bytes" -warning 39845888 -critical 42991616